I have a buyer that won 2 different single pony auctions from me Sunday July 23. I sent a combined invoice the next morning with shipping cost reduced to of course try to save the buyer on postage. I get home from work Monday afternoon and see that they made payment so I proceed to pack up the 2 ponies when I logged in to paypal and see they only paid for 1 pony. I have my eBay preference set for the buyer not to be able to change anything in the eBay checkout....... So I issued a refund with a note explaining what happened and resent the combined invoice. I wake up the next morning and the buyer sent payment again for only 1 pony and a message through eBay wanting to know why I refunded in the 1st place. I messaged the buyer back explaining why I sent the refund and that I had sent a note with the refund and explained that they have only paid for 1 pony. So I sent an invoice for the 2nd pony asking for payment. The buyer messaged me back July 25 telling me the eBay checkout won't let them pay??? So I sent them a money request directly through paypal that included the eBay auction title and item #. I went 5 days with no further communication from the buyer or payment. The buyer messaged me today July 30 around 2:45pm est saying the still have no option to pay... I reminded them of the money request I have sent them through paypal and directed them on where to find the information on eBay's customer support page on how to directly pay for eBay items through paypal. I have shipped out the 1 pony they paid for this morning because I didn't want them opening a item not received case against me since I held the item for 6 days trying to save them on postage cost. So has anyone else had issues like this with eBay's checkout magically un-combining invoices when you have your preferences set to not let a buyer change anything in the eBay checkout?   I'm just glad I was paying attention and did't ship both ponies when only 1 pony had been paid for.