Useless service and communication

An account has been opened in my name almost a year ago. I was informed by ITCBA (an out sourced company dealing with Avon's outstanding accounts) that I owe round about R4000 to Avon for items purchased. I told ITCBA that this was not me and that I suspect that someone is using my identity as I have never purchased anything from Avon. I even proceeded to send an affidavit in February 2021 with no reply from anyone. I have also tried to contact the company on numerous occasions with no answer on phone calls or e-mails. They keep on phoning me and I explain the situation and what has been done from my side to get it sorted but they are of no help. The call representatives are of no help and nobody gets back to me and when they do they just say I need to pay. No one takes the matter further and tries to sort it out. There is a serious miscommunication between this useless ITCBA representatives and AVON. They phoned me again yesterday and the person said I must sort it out. Never have I ever come across such bad service even from a company I have never even done business with. What must I do to get this sorted. How has no one made a note saying that this person's identity has been ****** and they must not send more products to them.