Maybe they could....
Such a shame that a communications company is showing itself so bad at managing communications, yet so typical. I just wonder how hard it would be for TalkTalk to offer a service to autoforward mail to an address chosen by the customer (that would be the person who has been giving you money for this service). Something like that should only require minimal hardware/cost but gets you maximum brownie points. You could even leave it running for several months to ensure and effective transition period and earn even more brownie points. Soon you could have enough to pay off the debt of one poor decision.