Help with refund, I keep being told I’m unable to issue a refund

Description

Hello! I sold an item on depop yesterday just because I no longer needed it. Turns out, I need to refund the customer and depop claims that I can only do so on Paypal. The money sent to me (through goods and services) is pending and I am unable to refund it. I tried to resize my paypal website, call paypal, and go through the message center with 0 luck. I keep being told that I’m unable to issue a refund. If I decline the payment, is it the same as issuing a refund? I am really stressed out and unable to get anywhere with this issue.