MTN-appalling service and feedback

I have NEVER in my life experienced such poor service. We have been owed money by MTN since June this year. They finally processed a journal entry into our account ...AS A DEBIT !!!!! this was then eventually reversed....after many emails...but we still are owed the original money money. It has not been credited to our account. In addition , the upgrade I signed for in September was incorrectly loaded and when I was refused the package which I signed for ( contracts signed and submitted) I requested to revert to what we were on prior to the botched "upgrade" a lesser package has been loaded instead. The feedback from customer services is appalling -the worst I have ever experienced in my life. Im really sorry we signed with them-AVOID !