MTN - poorest service i have ever received!!

Poorest service ever since I have opened my contract. The lady has selected the incorrect promo codes with an amount that was alot more than what I was approved for with the incorrect device and data package.I have since than spoken to managers and sales where no one wants to assist at all where they have started blocking me, reading my messages and not replying at all. Every month they stop my MTN services due to the outstanding amount that MTN has to pay . This is a hassle every month!!! I will never in my life take a contract with MTN again and this was my first time with MTN. I am disgusted in their customer service!!!!!