Why doesnt paypal release my pending balance?

paypal holds my funds when i sell some thing on ebay for 21 days unless seller leaves postive feedback but the seller never left me a feedback i contact the buyer 3 times but no answer. it has been 22 days already and paypal didnt release my funds even though it say they hold it for 21 days. What could be the problem paypal and ebay are starting to geting me angry when i ve been selling for almost 2 years