The worst company ever

I paid and closed my account 3 months ago. This was confirmed and i received a letter. Low and behold i wake up this morning i wake up to an alert that MTN has listed me as they continued to bill me. Not only was that the joke they dont action any errors they have made nor respond to remove this listing and close the account. Its one poor sole trying to do everyone's job Norman, he should be the CEO. Im not even sure what the designated positions to action these problems are doing. Im so so angry