Falsely handed over with proof

So I've been handed over, for absolutely no reason. I got a call from a different company to inform me, my account has been canceled due to missing payments. I have not missed payments and I've been paying CellC every month. CellC has no idea what's going on and the Debt collectors know even less.

BUT...CellC called me and admitted their mistake, told me it was their fault, but they can't do anything about it, meanwhile, my Credit score it dropping because I'm not paying my account, allegedly...I have the recording of CellC admitting their mistake, I have proof of my payments to them...soooo