MTN POOR CLIENT SERVICE

I have 2 data contracts with MTN .One is for 2gig day and 2gig night cost R100.In FEB 2018 i signed up a promotion deal that was 10gig plus mtn give anather 10gig on promotion.So its 20gig day and 20gig night for R299.My monthly bill must be R400.That is what i was sighning up for.For 5 months now my debit order is R800.Thy log a complained at the store i took it out from a week ago.Thay told me it will take 48h for feedback but a week is going by and still no feedback from mtn.This is not the first time i have a bad deal with mtn.Privious contract MTN charge me VAT on VAT on my phone deals.It took 4 months to sort that one out and i did not get all of the money back.I will move back to vodacom if this is not sorted out.