Still waiting for my refund since from July 2017.

I have filed my tax returns in time on the 13th July 2017 with all the supporting documents submitted and up until today have been waiting for refund which is due to me.I have confirmed with their call center that there is no outstanding requirement, have been to SARS offices more than 5 times and with more than 10 calls made without any help.The turnaround time I was told about has long gone past. Can somebody help, what must I do.