N Power Grrr - Can they do this????

I moved into a new house 2 years ago and immediatley started the process of changing energy suppliers.

I finally changed from N Power in October 2002 (yes, 2002)

I have received a bill this morning from N Power, which they say is the final bill.

It isn't for a huge amount but I foolishly don't keep records for company's I no longer deal with for more than 2 years once I consider the account settled so I have no way of proving whether the bill is right or not.

I spoke to them this morning and they were less than helpful. They blaimed it on the new supplier and said it had taken them 2 years to provide the final reading. I did point out that if I waited 2 years to bill a customer without any communication (i.e a letter every 6 months saying they are still awaiting the final reading) my customer would think it was a joke and refuse to pay. The man in the foreign call centre thought this was funny and laughed!!!!!

Grrr - N Power >:( Grrrr - Foreign call centres >:(

Getting to the point, I considered this account settled but have no records to prove it, can they do this? Is it legal? Is there anything I can do ???