What do I do??

I returned a shirt 3 days ago now. It says it will return on the 7 day mark of when I became able to return if that makes sense.

They sent me an email asking for the proof that I sent the receipt. They still haven’t gotten back to me and the status hasn’t changed on depop. Do I follow up with a new email to the support email in a new thread with all my info to make sure?? I ordered a new one in a different size so I really need to make sure I get that $$$ back. Also me and the seller had a bit of a dispute so I’m just nervous. I don’t know if they need to respond ?? I don’t know if anyone else has returned things and had similar things happen??