Sorry, you pulled the trigger on the negative feedback way too soon. Also, you should have contacted the seller before you bid if you wanted to make payment arrangements.
I have sold literally thousands of items on ebay and I know that sometimes things come up that are beyond our control. Bidders need to realize that many of the sellers on eBay are just ordinary folks working from home and trying to make a little extra money. You could have just gone ahead and paid on Friday if you didn't hear back.
This is one of the reasons I know longer sell on eBay. The sellers are at the complete mercy of the winning bidder and have no recourse when negative feedback is received.