Mtn contract sim swap 38 hrs not sorted

My name is khululekile .This weekend I lost my phone,monday at 11 am went to mtn store to do a sim swap.the lady was friendly and professional payed the amount of 115 and promised my sim will be working in 2 to 24 hrs,now 38hrs later simcard still not working.and I call their customer service only to be told I must go back to the store because "they dont do the sim swap over the phone".this is time and financial consuming I spent 38 hrs without a sim card.and now i have to take a leave at work again for fixing a simcard that I got from them,are they going to give me another simcard?,must i wait another 38 hrs tobe told I must go to mtn again? Because no one wants to take responsibility of fixing the problem