Mtn's negligence annoys customer!

I have been a faithful client of Mtn for many years. I had an approximate airtime balance of R5000 yesterday morning. For reasons unknown to me, my airtime disappeared! I brought this to the attention of the MTN call centre as well as their main branch in Umhlanga. I had been told by MTN that there was a problem with the IT side. I asked them to attend to the matter urgently. However, all they could say is that they will have the matter escalated and it would take 3 to 7 days to have the matter rectified! I think that's nonsense! No one has contacted me until now. I'm totally disgusted with their attitude, especially when I did not commit any wrong doings. The 'fat cats'(people in charge) are inaccessible! I have been terribly inconvenienced and I have lost business revenue because of this! If one of their clients had to pay their account late, MTN would be fast to suspend their line! I think that this is absolutely ridiculous to suffer this sort of prejudice!