MTN's service sucks!!!

I was overseas and reached the limit of my package so I could not make any calls. On Saturday, 11th May 2019 I called in at MTN's Sandton City office to rectify the situation and they said I need to "top up" - so I "topped up" for R100-00. However, all of Saturday, Sunday and today their system has been faulty so the "top up" has not worked. I called in at MTN's Eastgate office just to be told that "...IT are fixing the problem so you'll just have to wait..." The problem is that I have already been waiting for 3 days and they won't refund me with the R100-00 so that I can move my contract to a service provder who takes better care of their customer base. MTN sucks...!