Refund not yet received

I did my e-filing on the 3rd of July for me to get my rebates. I did and thereafter I was then told I should go to my bank to get a letter which I got so that they can confirm my new bank details. On the 18th of July I then did and the turn around time is said to be 7 days which you can get your refund, sadly 7 days has long gone past, so now I keep calling and I am being told there is nothing they can do. I want my refund back please.