Withholding refund due

I ordered a product on the 1st December. They delivered the incorrect product. I needed to show them the picture 4 times. They said they would replace with correct product, but after weeks of waiting, I asked for a refund. I have been told 3 times now the money will be in my account in the next 7 days, then nothing. Then I needed to send proof of account. I am beginning to doubt if I will get my refund. The experience has been really poor. As a client I should not have to beg to get my money back. I will never buy from them again.