MBD wanting to speak to the dead and wrong account holders

MBD Credit Solutions had been harassing me every day now for the past 3 werks via SMS and phone calls (calling from +***). They are Debt Colletors for their v customer Rand West Municipality which is the municipality of Randfontein. They continuously call in connection with a municipality account for my late (DEAD) mother. She passed away 2 years ago, and sold the house nearly 4 years ago. Of course she had to pay the municipality to transfer the account into the new owners' names on a zero balance. Somebody at Randfontein municipality clearly did not do their jobs, and now I am being harassed by MBD for money my late mother does not owe - ironically the municipality owes my late mother nearly R4000. Repeating the same explanation every day just to be ignored by MBS is getting infuriating! How many times must I tell them that I can not put my dead mother on the phone, and that the debt is not my late mother's debt? After about 30 phone calls repeating the same information, I have had it! ***