Buffalo is not refunding my R10 516.00

I made gravely mistake of paying R10 516 instead R105.16 on the 31st March 2022 and I informed Buffalo Intl Logistic immediately. They sent me a reversal payment form, which I completed and resend immediately. It is almost a month, trying to get Buffalo Intl Logistics to reverse my payment to no success. I call them everyday during the week and it is always the same story that refunds are only processed only on Fridays but 3 Fridays have past without any refund. I am not sure what more do I need to say to them to get my money back.