FNB connect - kicked me off the network for no reason

Usually I have no problems and have been with FNB connect for years. Since this weekend though I can make no calls or receive any calls. My mobile data works great no problems. (I have enough call time)

As soon as I try to make a call it drops tells me I'm not registered on the network even though my data works fine. Even tried putting my sim in another phone. SAME PROBLEM. Bottom line is I can't even contact 135 since it drops the call before it connects.

So it is obviously not a device issue. It has been 2 days without communication. This needs to be sorted out !!