MTN customer service

I’ve been with MTN for more than 20 years and with every upgrade of my phone, my credit limit is changed. I normally run out of credit in these case when I’m overseas with no way to phone MTN to fix it. I have three phones on my contract so the limit is quickly reached. This time the limit was cut down to R3000 from R19000. I was already at that limit when I upgraded my phone so it ran out of airtime immediately. I logged this with MTN on Wednesday 18 November and was told they have a three day response time. Followed up on Thursday and was told on Friday that it needed to be escalated, another three days. I followed up today Monday 23 and was told that it needed escalation to Vetting, another three days. I also need to submit three months bank statements as well as paysheets. I have been on an MTN contract for more than 20 years and I’m now being treated as a new customer. My job requires me to make several overseas calls every day but I’ve been unable to do my job since Wednesday last week. I feel this is unacceptable treatment of a long time customer. I have now already signed up for another 2 years so no way to even get away from this service provider.