MTN: Dreadful Service

I have been a MTN (2 X cellphone contracts) customer for approximately 30 years. For all this time I have payed monthly by debit order; therefore never in arrears. Earlier this year I was advised that I could upgrade one of my cellphone contracts. This morning I tried unsuccessfully at the MTN store at the Whale Coast Mall in Herm**** to do so. The unsuccessful process lasted about 3 hours, The ID and vetting process did not achieve the desired results. I gave up. Subsequently, once home, I received a call from the shop that MTN needed 3 months worth of bank statements (ABSA Private Bank) in order to finalise the vetting process. I also received an email stating that I require 3 months worth of bank statements. The implication being that my payment record at MTN means nothing and that I have wasted a whole morning achieving nothing. If this is the way that MTN treats their existing customers then they do not need any new customers or in fact the business of loyal, existing customers.