Worst contract upgrade experience

If you want to take a contract with MTN just get ready for hell. I've been a loyal customer for years and I have been on multiple contracts with them this current one did an upgrade in July the guy called me on the 13th of July told me they are giving me a 30% discount if I did my upgrade on that day. I specifically asked about the premium and he told me that the last premium for the contract I had would be paid endf July and from August I would be paying the new amount and guess what I paid the premium for July but in August my premium was more than triple the amount and currently the premium is way above the amount the guy told me repeatedly on the call. I have emailed their complaints department that was absolutely no help the guy who dealt with my query did not even bother to check what I had asked about I asked them repeatedly for the call recording and they never responded to me MTN is the worst service provider if I could rate them minus 1000 I would they are absolutely uninterested in their customer service they will tell you one amount when you upgrade but will charge you way more and refuse to help you