Poor service experienced

Is anyone experiencing poor service from mtn. I am disgusted I am an angry client i can say. My husband an O Joint mtn 24months ago we took 2cell phones with mtn sim apparently when the contract ends they lock your sim card . Then when debit order bounces they also lock your sim card not knowing why it bounced, they provided clients with FNB account to make payments on if they did not pay in time but the FNB in question is no longer working apparently the account is no longer existing and they've told clients..which clients? Mtn gives you sim card with their contract and deactivate sim card at their own time when they wish to do so...not considering how many important calls you will miss a day...we tried to send POP to about 6 six of their consultants to allocate Payments that were paid to their no longer working bank account, but no action taken on our enquire.. its been 7days now

I will not recommend mtn to even my worse enemy