Port my number

I want to move my number to MTN. I was told to cancel my phone and go on to pre-paid as Altech is useless in porting numbers across and take extremely long. I called cancellations and spoke to an extremely rude/aggressive lady that didn't give a damn. She advised that I missed the cut-off of the 10 and had to wait until end of August. Point is my contract expired the 9th which was a Thursday. I went to Clearwater Mall on Saturday only to be advised that they had closed down. On Sunday I went through to Princess Crossing as well to be greeted by big bolts on the door - closed down. I called the Service desk only to be advised that I can't cancel my phone with them I need to do it during the week as they are closed. What I now would like to know is how can I meet a deadline of the 10th if I am not aware about it. I want the shortest possible way to cancel my contract and port my number to MTN. WHO IS GOING TO HELP ME. I don't want to speak to another useless person that doesn't not know what customer service is.