MBD DEBT COLLECTOR HARASSMENT

So after Cell C didn't cancelled my contract with them they gave me over to MBD Debt Collectors. So with fights and a lot of swearing I paid the cell C, against my husband's advice. I've send through a letter from Cell C starting that I have paid the account in full. Now MBD phones me every single day sometimes up to 4 times a day. Also received a SMS that my Cell C account is outstanding with R420. Everytime I'll tell them to check the emails that I've send. Landi Soldaat from Cell C also send in a request to them to take my name off. But still they are phoning me. This borders harras*****t!! The way they talk to you also problem. And they can't give me someone to speak to who speaks Afrikaans. I see on the other reviews they give like a automated message. So let's see what they will do now. Next move will be to contact my lawyer.