Store Forgot To Give Me In-store Credit Slip For A Return I Made And Refuses To Give Me Money Back

About 2 weeks ago I bought an item from Pick n Pull, it was an e-brake assembly for $15. I ended up returning it, and during that return, I noticed on my receipt that they falsely charged me for a $5 door handle that I didn’t even buy. They offered to return that too, so in total it was a $20 return.

Now, I didn’t know this at the time and they never told me, but Pick n Pull only does in store credit and they’re supposed to give you a neon green return slip. When I returned my item I distinctly remember him writing on the green slip but he forgot to give it to me. In all honesty, he looked baked out of his mind, so that’s probably why. I didn’t think anything of it though, because I didn’t know what the green slip was or that they only did store credit. I thought the money would just go back to my card

A week went by and the money never showed up in my account, so I went back asking if the return went through and they said “Oh, we don’t do money returns, we only do in store credit. You should’ve gotten a credit slip.” I told them I never received the slip and they’re saying there’s nothing they can do. They said their transactions reset daily, so if I went back day-of I could’ve gotten the slip, but now they can’t do anything. They essentially lost me $20, $5 of which was a false charge of an item I didn’t even buy. Is there anything I can do? I still have the receipt of the return.