Loosing business thanks to MTN

Shocking!!! My business lost money because MTN can not get their act together. Every month I am out of the country and as a standard, my international roaming is switched on and active...so again I arrive in the USA and for the first 2 days everything is working (as expected) and on day 3 it stops working. A week later and after many hours online and getting people to help on the SA side to help I am still cut off from any and all making and receiving of calls and the whole MTN just pulls up their shoulders.....shocking service