Unhappy customer Debt Busters

Our debt review gas been paid up in full since February this year... one consumer alleges that we still owe them money. Debtbusters stopped paying them in 2018 already. I have spoken to 4 consultants since then to get it resolved. Still no resolve. It is a difficult thing to make the decision to go under debt review and that in itself has already been horrible. Now I am battling to get my name cleared. I paid them every month in time with the idea that the admin and management of debt is done. Today I spoke to a consultant again and was promised that a team leader will call me back. No call was received. I understand that all businesses are under pressure due to lockdown, but surely they can still provide a proper customer service.