Harassment over incorrect information

I am currently under debt review with Debt Busters and have not missed a single payment. I am now, however, being harassed by Barrett and Associates for an account that payments are being made to every month under debt review. Both FNB and Debt Busters have confirmed that the account in question has not been handed over, with supporting correspondence. Yet Barrett and Associates continue to harass me and threaten with legal action. Get your facts correct!!