mtn-worst experince ever.

Good day all I have had the worst experience with mtn as they have now twice put a default on my credit report that i have worked so hard on and the first time i struggled from pillar to post to get it sorted but to no avail and had to go through almost 2 years with that default on my name and this month they defaulted me again. Mtn i have opened a data contract with you guys and in the 2nd day was not happy with it so i cancelled, paid and closed the account, but you guys are still billing me and now im in defaulf again!!!!!!