Roaming never re-solved since October 2014

I have had endless trouble with my International roaming since October 2014 and it just doesn't seem to be resolvable. I travel a lot overseas and often for months at a time and rely on having International roaming to be in contact with family. In fact I've had it working for the past 5 years, then suddenly Oct 2014 no-more! I was recently back in SA and renewed my contract for a further 24 months, which honestly appears to have been a waste of my time and my money because MTN are billing me for a service I'm not able to use!! I have been dealing with Sandile at Clearwater Branch who assisted me with new contract in April 2015, and he has been a super person to deal with and he too has been trying to assist me with this problem ( REQ:***) but clearly something else is wrong because it's not resolved! I still have NO SERVICE!!! Extremely frustrating!!!!