MTN Roaming frustration

I activated SMS Roaming services from MTN for a trip to Germany, however, upon my return it has proved impossible to reconnect to the MTN network. I have followed the initial instructions received from MTN (upon activation of roaming), Googled various other options and even went to a MTN store. The advice received was to "wait a while". I have now waited 4 days without being able to make/receive calls or use mobile data. If I knew this before my trip, I would've never activated international roaming. Truly frustrating!