Worst service with Mtn Pavallion

I am very disappointed with Mtn. I have bought an iPhone 7 on Friday 11/09/2020 and it had a problem with the charger. I returned it to Pavillion mtn on Monday the 14th. I've been going to the store and contacting them and keep on referring me to different departments which I don't understand why. What irritates me the most is that i was billed for this phone on the 1st, they billed R1130.9 but the contract is R369, mind you I haven't even used the phone. I had the worst service ever