MTN Greenstone and MTN head office

I signed up for 2 contracts beginning October 2018 (1 x upgrade , 1 x New contract) after MTN Greenstone staff never called me back and 4 days after waiting for the phones and threatened to cancel the phones I ordered were only available as the ones booked originally as per the sales lady was never done. Now 2 months later I realized the one contract as per signed contract of R169pm I am actually charged R239pm and the shop I upgraded at says it not their problem to resolve as this is a MTN error and not theirs also they put the phone down in my ear both sales And manager as they said they won’t assist as I am not allowed to get angry at them , MTN call Centre cannot pick up or resolve the problem immediately nor even apologized about this only says they will investigate , not when I will get my money back or when it will be sorted even though I have a signed contract. I told them the phone is still new and sealed they can cancel the contract the shops response was then I will be charged cancellation as per contract , funny how they are allowed to over charge on a legal contract that isn’t right but if I threaten to give the phone back and cancel I get told I can get a lawyer if I want and the shops also responds in saying that how come I only realize this 2 months later ..... bunch of ****** MTN and MTN greenstone service from the start to now