No outgoing calls

I have an FNB connect line on Talk Max. For the last seven days I cannot makes calls to any Vodacom number - the automated message is that there is insufficient airtime. The matter was resolved for a day and it’s back to the same. But I can make calls to MTN. Many calls and many hours of frustration, it still does not work. Now when you call 135, I cannot get through to the call centre. Frustrating service.