Bad service

I have been struggling since last year with Cell C. My father died, after numerous months, emails and phone calls his account was transferred to me eventually. Now me and my mother are being harassed by Debt collectors looking for my dead father, saying he owes money. Then when Cell C phoned my mother sometime, they advised her that she can just ignore the smse. I sent through a few emails to creditqueries, they confirmed that I don't owe money, I have a debit order.

I just received another sms from CSS stating that I owe money and that further action will be taken against me. So please can we sort this out.