No, eBay won't close your account, but the seller may get fed up waiting and cancel the sale because you haven't paid. If this happens you may get a non-payment strike from eBay. Strikes stay on your account for a year. One strike won't prevent you from buying here, but if you were to get a second most sellers would automatically block you from bidding.
Keep on trying to contact the seller - eBay messages are a bit erratic!
To prevent this worry in future, don't bid for items unless you're sure you can pay within four days after the listing has ended. That's how long eBay gives buyers to pay before the seller can cancel the sale.
