Supercharged

I upgraded my cell phone device in September 2018 knowing that it was 3 months early to qualify for an upgrade. I was aware that i would have to pay and extra amount on my first bill for the balance of the device. I received a bill in October that included this fee which i paid. My November bill should have been my normal contract fee but received a bill almost 15 times higher. I logged a complain on the 5th of November and after a week i made more phone calls because i didn't receive any feedback, all i was told was that the case is still open. I even went to a telkom store with the same feedback. After 2 weeks of no feedback they opened a second case. Yesterday afternoon 18 days later after several phone calls i received an SMS stating that the issue has been resolved. When i looked into my account i saw that it was still the same amount. i phoned the call center again and all that i was told was that "The customer has to pay this amount".