Builder Bill...court awarded in his favour i knew nothing til 15 mins ago

Good evening...a little background is needed here. Last year in late spring decided to have some work done to our property which was to be done by a good reliable friend. But unfortunately a new contract for his company saw him working away so we lost him. Had a couple of local people come around and then a friend mentioned that someone he knew and his two work mates had been layed off by their company down to lack of work. I met the chap seemed nice enough discussed in some detail work required he did some drawings and gave a couple of prices stage 1 stage 2 etc. The fact they could start almost immediately was a plus for us and so the building work started. The completed stage 1 was ahead of schedule not as much mess as anticipated and everything seemed fine. Stage 2 turned out to be not quite as smooth but they were a nice bunch and seemed enthusuiastic and work ticked along and `good` progress was being made. A few silly mistakes turned up along the way which were annoying to both parties but they were rectified accordingly. We then had a period when the job was coming towards the end on my property and work was started on my elderly father in laws property when everything seemed to be in slow motion.. painfully slow at times with me saying "so whats been done here today"? a good few times. Work went well at my inlaws and when bits and pieces that were needed for my property were delivered one of them sometimes two would go there. Having done a snagging list for my property and it sort of being rushed through and later finding quite a few issues we were glad to have zero builders in our property. The work was finished at my father in laws and one or two problems arose. The chap most local came back sorted a couple of minor issues and said he would make the other chap aware of the unfinished items...to be honest my father in law was going to have them back to do more work but wanted a break from the noise and mess too. The work ended im pretty sure towards the end of last July . We then had a visit from one of the builders who had left some ladders at the side of our property and when he went to collect was really cross as some outside pipe work had not been completed. He said he would inform the others re this. During all the work the builders were payed weekly mostly cash as they asked for it but some cheuques as we didnt always have time to sort the cash out with banks. Materials bills were popped into the equation as the work went on and again duly payed. When skips were required if i was at home i would pay for them. When i had contacts for some plumbing items or double glazing or flooring again i would pay for them this was done without fail or any problem at all. Remember this is now at the end of July...forward to the day before new years eve and i recieve a voicemail message from the builder saying he had had some final bills in and there was a balance of £1500 due. I thought in all honesty this was a joke or a prank of some sort and was thinking of a funny retort or reply but with people staying with us and a busy house didnt. Anyway forward to the bad weather and low and behold the outdoor plumbing came back to prove it should have been done as we ended up with water backing up an pouring in through our kitchen ceiling. In the midst of trying to decide if to call the builder or our insurance company i recieved a text from said builder saying he hadnt heard from me and needed to speak to me. Well as i needed my leak sorting he got a call and i asked him to pop round. He was duly shown the leak took a saw to an outdoor drain pipe and the leak ceased. I then asked him what all this was about trying to ask for more money and he said it was an invoice that had come in late from someones account he had been using for materials on my father in laws work. I told him im sorry but its way too late to start trying to ask for things now so long after finishing the work and not making any form of contact at all. I told him i was very sorry but no i cant help you. I went off obviously unhappy claiming it was affecting his income not being able to use this other chaps account and he felt it was all wrong and off he went. Probably a month or so later via recorded delivery he sent a bill made out to himself from another company with no items identified just stating `materials supplied` for about £2400. I was livid but calm. Then nothing not a thing. I spoke to a few different people about it in confidence and they all said hes trying it on or words to that affect. It was left that was until today when i arrived home and opened my post to find that my local court had awarded him over £2600 and i was to pay it in full before the end of the month! I knew absolutely nothing at all about a court case and need to know were to go from here. Ive just read this back and i didnt realise how much id rambled on...sorry. Just to add he had a little book he wrote things down in i take it money etc we wrote ours on last years calender which we threw out in the recycling before we knew of any of this and at no time was anything signed by either one of us. Where do i go from here...help i feel a sleepless night coming on and we are away on holiday next week too.