Gatvol service and system

From the 21 of May I have been trying to get help with my pre paid sim card ; that suddenly gave an error that "no network connection " called the call centre and I was asked stupid questions; which I failed to answer . Then was advises to recall my transaction and call back; on which I can't. Went to the Mtn outlet and they also couldn't assist me ; as I was not getting the questions right. I have the faulty SIM card; proof address and my South African Id ; i just dont understand their system ; And why would I de***** myself cause I believe that is enough to verify me.