Almost 2 months and my refund is not complete!

I went in Game on the 15th March 2018, I had incorrectly made a payment of R4 500 into the account. Yes it was an error on MY side. I did, however, immediately go to the credit desk at the same game store and reported this. I was told I need to provide a bank statement, I could not at the time because the transaction would not reflect so soon. The statement was then forwarded on the 12th April 2018, and today (20th April) over a month after I get R 415 back! What about my R4 175 that is still due to me !!!! Those funds are meant for something else and over a month later and no joy !