Unisa Studies Fees Paid but does not reflect

I am registered with Unisa for a course, and my tuition fees are paid in full. Automated emails are frequently received that my studies fees are outstanding and not paid. Problem is I cannot get hold of anyone at Unisa via telephone, email or campus and my first assigment is due 10/02/2020 which I do have the study material for, but my account is still blocked due to fees not paid according to them. I am really desperate to get this sorted out as I wish to start with my studies.