MacBook Pro trade-in refund to purchase, not credit card?

I recently bought my new macbook pro two weeks ago but forgot to bring in my trade in when I bought it. I went back brought my computer to do my trade-in, however when the amount was refunded to me it didn't go towards my new computer. It went to my credit card balance. My question is is there a way to dispute it so that the trade-in amount goes towards my computer instead of my credit card bill? I have messaged apple and one representative tells me its possible but then another one tells me its not. I just want to lower the cost of my computer because that was the reason for my to trade-in my old one for my new one.