BT account not closed on joining PLUSNET

[#1]

I've just discovered that the old BT account was not closed when I joined Plusnet FIVE years ago. (my fault for not spotting it) - surely BT and Plusnet would between them have sorted this?

BT say there is nothing they can do to reimburse me - but I'm not so sure.

Does anyone have any ideas?  The bill runs to thousands of pounds!

TIA

[#2]

@LHolman BT broadband and Plusnet are two completely different entities, closing your BT account can only be done by BT, it is not possible for PN to tell them how to run their business.

I'm somewhat amazed you haven't noticed you were paying them for nothing over a five-year period, but all I can suggest is you get back to BT and tell them in no uncertain terms that it was their error and they need to sort it.