Refund Issue

I paid a registration fee in 2019 for a course I wasn't able to study and I have been trying to get a refund but I'm told that without a deposit slip which I got from FNB ATM after depositing I cannot get my money back. I mean the only thing preventing me from getting my refund is that stupid deposit slip. Isn't there something that the university can do because the funds clearly reflect under my student account and it clearly shows why the deposit was made. So just like that I guess I must just forget about getting that money back. Please do something because times are hard now and I really need that money!