Magistrates contact me 2 years after confiscating vehicle

I was stopped by the police in summer 2009 and my motorbike was confiscated and crushed due to me having no insurance or tax. My fault, understood. I was told I would incur a fine and be contacted by phone or post and would get a court summons. I heard nothing in the following months and moved house around 5 months after the incident. I received a phone call today from Poole Magistrates - over 2 years since the confiscation - informing me to pay a fine of £650 for this incident. They say they tried to contact me by post but I was no longer at the address they sent the letters to, leading me to assume they must have sent the letters at least 5 months after the incident in 2009. This doesn't seem right to me. Can they contact me out of the blue almost 2 and a half years after telling me I would be contacted and now tell me to pay a fine (and who knows what else following the fine)? I was told I have the option to dispute and take it to a tribunal, but I need to let them know by tomorrow. 

Thanks

Elliott