Transfers to bank take 3-5 days. PayPal mark it Completed because they processed your request to transfer, it does not mean the money is in your account already. Then you have to wait for your bank to process the request on their end. The funds are processed in batches and have to go through the clearing facilities in the ACH system to your bank.
On every Ebay listing,it should say where the seller is and where the item is,and how long it would take to arrive.
You canno file item not received before the estimated date of arrival.
Chinese sellers often sell under multiple IDs and have many listings,they are not good at answering emails.
if item has not arrived past the estimated time,then file with ebay.
Paypal is a payment processor,you tell Paypal to pay someone and it will do as told,of course Ebay may decide on holding on to the payment if the seller is new,high risk or high dollar.
Did you try a phone call?
What was the dispute? What offers did you make to settle.
My approach is to learn as much as I can and then present my best offer to the buyer and make it such an offer that the buyer is likely to accept. You stay in control this was. Once you pass control to PayPal there is a lot more to lose. Once you pass control to the buyer to return whatever, your business cost goes way up.
If this was eBay, does eBay allow a seller to cancel a purchase arbitrariy?
If the website has rules that were violated, then report the seller.
PayPal allows seller cancellation arbitrarily.
In future don't use this seller. Better yet ask the seller about cancellation policies in advance.
Do a Google search for the business.
Send the seller an email and ask all the questions you want about the business.
Ask for a physical address to you can verify the location on Google maps.
As for a phone number so you can talk to someone at the company.
There are a lot of ways you can investigate and learn about a company--and you should. Never rely on PayPal to fix a purchase gone bad; you need to trust the company, so do your research.
PayPal will not protect you from back buyer judgement.