The buyer had paid by PayPal. I just got off the phone from ebay and they have escalated it to the technical team. Does anyone know if I can post it using click and send still with the ebay satchels? Thanks,

Yes, you can still use the eBay satchels with C&S (until I think November). You can no longer use the eBay codes. If the item is 500g or less send it as a normal 500g parcel in C&S using your satchel as Own Packaging for $7.20. 500g C&S satchels cost $8 and the 3kg satchel now costs $13.05.