Mtn not secured

Sim swop/hacked Yesturday I just saw om my phone whatapp logged out... hacked Someone hacked my sim. So how can MTN let someone not with my identity can be allowed to do a sim swap!!!!! So I hold MTN accountable for this!!!! How can they let this happen, now the hacker whatapp all my contacts, asking for money!! MTN IS NOT SECURDE ENOUGH!!!