Unnecessary Telkom stop and NO receipt for money paid

So last month for no reason that can be explained to us our sim card stops working. This month the same thing happens to my daughter's SIM card. Each time it costs us R99 to do s SIM swop. I would like know to exactly how many Telkom customers this is happening to !!! Also the guy at your cape gate branch on Saturday the 7th of February did not give us a receipt and neither did he give us change for our R100. They just looked at us like we supposed to leave without it!!! Can someone please give us an explanation for this!!! Is this standard Telkom behaviour