15-02-2021 3:26 PM
Sellers can block buyers for several reasons:
https://offer.ebay.co.uk/ws/eBayISAPI.dll?BuyerBlockPreferences
If you don’t meet the seller’s buyer requirements you would have been told which one, so you could correct it.
As a last resort, if you cannot contact the seller and there is an option to cancel your payment in PayPal, do so and buy from another seller.