Ebay resolution centre timelines help!

[Melfish]

I sold an item on ebay last month, stupidly I did this on the app and none of my usual selling restrictions, e.g. Blocking bidders abroad etc worked and a non UK buyer won. She provided me with a UK address via paypal invoice. I checked with ebay customer services and they said it was fine to post and confirmed about the app's shortcomings. I sent the item by recorded delivery.
Unsurprisingly she has now said she has not received the item and has opened a case on ebay.com. I have provided her proof of postage via the royal mail website to the address she provided. I have not heard back from her since. The funds associated with that transaction are frozen in paypal. Does anyone have any idea how long it takes for a case to be resolved if the buyer does not reply?

What day did she open the case?
Did you provide recorded delivery details (the look up number) to Ebay?

have you got proof of delivery or proof of postage?

Yep, got signed for. If you go on the RM website it comes up with a pic of the signature and their name printed out. Have sent all the info via ebay's resolution centre messages and their current status is that I have to wait for the buyer to respond. Buyer opened case 20 days after sale ended.

I will never use the app again! Have never had a problem when sending to UK based buyers.

can't you escalate it to customer support?

I think I would resort to live Ebay CS chat to figure out what to do next.
Probably best to escalate, but unresolved cases are a dark art for me (luckily).

Ebay CS chat cut me off twice before I got connected to an operator. I did follow some guidance on the resolution centre selling section and reinput my tracking number- apparently my funds 'should' be released in 48 hrs, I won't be holding my breath tho.