This is really disappointing.
1. Get in touch with the seller. 99% issued will be resolved by eBay Sellers if they are trustworthy. Check feedback for trustworthiness.
2. Also Please write to inrswebhelp@ebay.com with the PaisaPay ids and mode of payment. i.e debit card/netbanking/credit card.
Also just for your payment security, initiate a Item Not received request in PaisaPay.
So that your payment wont be released to seller.
Hope this helps.
Get back here if you have any queries.
