Marius - sorry to hear - but try one suggestion
Try a live person through EBAY's "Chat" system. You'll find it easily enough under Contacts in your EBAY account. It usually doesn't take too long for someone to come on line to chat with you. Have the points of your issue typed out in advance (succinctly) in a separate file, so you can copy paste it into the chat form, which goes faster than typing and will keep the EBAY representative's attention better. Clearly somebody emailed the seller after the auction and said they would offer more money. The buyer listed it again at their price. That's what he is calling technical difficulties. EBAY will have a record of that email from the buyer with their offer, since the email will have gone through the EBAY mail system. Be reasonable, unemotional and brief when you chat with EBAY. Might go nowhere, or you might get their attention. Keep us posted on the results. Good luck - Bill