Please ask Nu Debt to stop harassing me

Nu Debt is forcefully harassing me for an account that does not belong to me. SARS has not recieved any payments towards your Tax, avoid further escalation.Pay R18854.15 tax no: which is not mine.Go to e-Filing/Mobi-App to initiate a payment arrangement.NuDebt ***

The consultant I spoke to this morning said, they will never stop sending me the messages because the person who they report owe them or SARS is my relative.

What is worse, the person has even received payment from SARS because it's SARS that owe her.

Please help me Helo Peter.