very angry soon to be ex customer

I upgraded with MTN in August 2019 and since then MTN has been billing me incorrectly, I notified the organisation but to no avail; in october the di manage to fix the one part of the contract but then from there onwards they did no fix the other. I have logged several calls and sent proof of contract but hey here i am still not fixed. I am now on the verge of going to Consumer onmnibus; the worst part is that they have changed the terms of the contract where the night data was from 12:am to 6 am to 12 am(which at times it doesn;t start at that time) to 5 am with the same billing and in the beginning when you take the contracted you are attracted by those benefits. If it was not for the penalties when ending the cotract i would have done it a long time ago, i cannot wait for the contract to end so that i move to the vodacom. My contract is 479 for phone and 299 for wifi; they manage to fic the wifi contract but not the phone contract which they are billing me over 550.