Mtn worst of all!!!!

I have recently upgraded my contract and I signed in store for a bill of R759. Now my bill is R1337. Mtn HQ says that is the price of the package and the shop showed me black on white in the spread sheet that the contract and bill they gave me is correct. When I phone MTN they send me from pillar to post and I get no where. I Alsol have three 1gb re occuring bundles added to my account which I do not know where it comes from and neither the shop or MTN customer service or self service can manage to csncell these subscriptions. I am at a dead end and mtn has no inclination of dealing with this. Two operators have put the phone down in my ears whilst speaking to them and I have submitted the reviews as extremely bad and not even had anyone come back to me on those reviews. After being with MTN for more than 25 years I am so shocked with the recent poor service!!!