No study materials received

I have registered for a subject, Labour relation management with Unisa.<br> I have paid my study fees in full during the end December, up until now I have not received any study materials, I have phoned Unisa and asked them if they can defer my module to the second semester as there is no time to cath up with my studies now as the exam is in May month.<br> Till today I did not get any answer from them.<br> I refuse to carry on with the module in this semester as the second assignment should have been submitted 16 March now because I could not submit the assignment it will influence my year mark this is not the first time that I struggle to get study material from the university and if you phone they don't answer the phones.