Poor systems, staff who are not customer centric or comfortable with systems, and full of empty promises

Its taking me a week to get my data sorted. I went into the Ladysmith branch and the lady is unable to go into the system (no backup), nor does she have any stock for me to take out a new router. I went to the Durban, Atrium branch with even worse service. I was promised a deal of 80gb for 249 and signed for it on Sat 29 April, with the promise that by 30 April, it would be sorted. Sandra and Muhammad promised to call me back and then didnt. Today, Sandra tells me that the deal is void because it expired on system. Its my problem that MTN had system issues, that MTN staff do not call me back when promised or that MTN dont have relevant stock after having advertised in store and online. I dealt with Mohammed too and he didnt even apologise. As a customer, i honestly am disgusted. Please get staff trained on system, with back up plans if they dont work and TELL the customer directly what you'll do. Not what you wont. Very disappointed.