MDB TOTAL HARAS*****T!!!!

I have an old cell c account that has been settled! I am constantly harassed with text messages that I had made an arrangement for payment! Which I have never done! The account is older than 3 years, and according to law you are not allowed to recollect on old debt even? There are also set times and days on wich collections may be done! This MDB obviously has no clue of what is going on!!!! I get text messages at all hours, and every single day for the past 3 months! Sundays, public holidays and after hours! Really!!!!! They say that there is still interest and collection fee’s outstanding! I did not contract you, and my account has been settled in full! I have sent an email to them as well as the debt council and still this harrasment does not stop!!!! How does one end this harassment!!!