MTN continues to go after our pockets

I got a new contract from an MTN store in Wonderpark which amounted to R345 but my bill came and it was R886. When I called the customer centre to enquire what happened they told me about being billed per rata because I got my contract just after the first of Jan. there was a separate phone charge, a separate calls charge, 2 separate data charges... but wait... theres also a R350 spend limit they didn’t tell me about (which adds on to my bill being over R800) and they wont be able to change it until after 30 days. The agent refused to forward me to her manger who was there at the beginning of the call but somehow vanished when I asked to speak to them. Im so disappointed that I have 23 more months with this service provider... I honestly regret getting that contract with them