Liberty Life failing to pay out and ignoring all our requests for communication

My father passed away in June and Liberty life was suppose to pay up the remaining balance on his home loan and pay the difference to my mother as she is the spouse and the policy belonged to both of them. For two months we have been begging them for feedback, after we submitted every document they required and the stamp for the bank. Everyday I call, i get told an email will follow but its almost 3 weeks waiting on a reply from the last call.