Poor Service Delivery/ Problem not Sorted

I have been struggling for the past 2 months to get assistance from this company. My email was hacked, and I need them to delete my Sanlam portfolio profile on app so I can reregister with my new email, but they have ignored all emails my HR has sent and have not responded either in writing or call. I have no idea how to move forward and am very unhappy with the service I've received. I feel they do not care about my problem. Others I know who had similar problems, they were helped relatively quickly. So am very disappointed that I haven't received the same service.