False Advertising on DATA-booster bundles

I received a call from an MTN Sales rep in September/October 2018 who wanted to upgrade my package. The brief of the conversation was that there will be a once off adjustment in my subscription and i would get 3 extra gigs on my package but that was a blatant lie from MTN. Before the "upgrade" i was paying R1864 and now my bill has been adjusted to R2 300pm. i have been calling MTN for days and days but no one could come to my rescue or advise what the problem is. I even spoke to a "Supervisor" Samukelisiwe ********** who asked me to send her an email to look at the query, still no response from her side as well which is very disappointing. i have been a loyal MTN subscriber since 1997, never missed any payments, but the treatment from them says the total opposite. False advertising, not getting back to customers, being posted from one call center to the next, incompetency, poor service = MTN!!!!!!!