Suspended line

Mtn they are so *********** my line has been suspended since Thursday and when I call they just reactivate it but within few hours again get disconnected. I have been losing important phone calls yesterday spend whole day calling them and they are busy telling me they are still investigating. This is so frustrating and draining had to wake up and call them today and now I'm being told maybe this issue will be resolved latest Tuesday I don't know what's so hard by fixing this