MTN: abysmal service and utterly obstructive consultants

I wish I could allocate a minus rating: MTN are simply abysmal. I upgraded my phone and contract on 27 January. The printed contract stated " Effective date 27 January." The consultant at the Mall of Africa store confirmed to me on 27 January that the contract was effective immediately. On 28 January I woke up to no usability. Back to the store, same consultant, he fiddled on his computer, and everything worked fine: he confirmed that the contract was in effect and working. My upgrade was to the Sky Silver package, which includes 50GB of data monthly, as well as some extra data specials. On 28 January, I transferred my old phone contents across to the new one, but on 30 January I received an SMS from MTN stating " you are incurring cost from your spend limit". I phoned to be told I had used up all my data as well as my monthly spend limit of R 4500. The consultant advised me that my contract was pro-rated from 27 January to 31 January. I was told to wait until I received my invoice and then dispute it. So I received my invoice, which is 6 times my monthly average: even when I have been overseas roaming I have never spent so much in one month. So I send a very detailed email to MTN, essentially stating that my contract kicked in on 27 January, so it was patently incorrect to state I had used all my data and to then charge me on my spend limit. I received a *****ic response, stating that the reason for the high costs was that I had used a lot of data. This was followed by an SMS stating that my query has been closed. So: I phoned. 4 consultants cut me off in mid conversation, and the 5'th told me I must return to the Mall of Africa store, as " your contract is with them".....When I told her that was absolute ******* she told me she cannot help me and cut me off. And I then received an SMS stating my query has been closed. So: I go to a store, to be told they can't help me: I must use the online help. Doors closed. Only option: Small Claims Court. I have been a customer for umpteen years, MTN's records will show that I never incur the kind of costs my latest invoice reflect, plus, in law the contract kicked in on 27 January, so I was entitled to the 50GB of data. Clearly MTN train their consultants to be utterly obstructive and work on the basis that the average customer will lose interest in the dispute. Pity there is no real competition in SA, as I would like nothing more than to take my business elsewhere.