Thanks whyme. The bit that's confusing me is that Moorcroft is chasing for a different sum so i think I'll try the SAR so that I know for sure it has been paid off.

I ran into a bit of difficulty last year and got into arrears with Orange. My service was blocked and as soon as I could I paid the outstanding debt, of about £148 by cheque directly to Orange. I received no more bills but then about 3 months ago, I got a letter from Moorcroft debt collection who said I owed £137 to Orange. I disputed this on the phone as I've received no further bills from Orange once the outstanding £148 had been cleared. Understandably, Moorecroft asked for proof of payment, which I sent in the form of a copy of the cheque. I foolishly didn't sent that recorded delivery and they claim not to have received it. I know that if the bill was still with Orange I should send an SAR but as its with a DCA, is that the appropriate next step? Very grateful for any advice.