promise to refund me within 7 working days

I had a personal loan with Nedbank. Because of some financial crisis I was garnished. But now they debited they money until it was more than what they suppose to take. Contact them for my refund. Which they send me from pilla to post. Nd told me they will refund me within seven working days. The seven working days has long pass. And no one once to take the responsibility. As in now they have not refunded my money. I find unfair cause now I had to spend my time my money to go to the bank. Even using my phone to contact them. While it was easy for them to just hand over my case to the lawyers add they interest. And when they default I should understand that they have. They have been telling me they have deposited the money even now nothing in my account. I truly want my refund and need to be compensated for they lies empty promises nd the inconvenience.