That 11 digit number will not relate to anything on ebay or papal, it is just a banking transaction ref. Have you bought anything through ebay for that amount? If you bought as an ebay and/or paypal guest, then it won't show in your ebay and paypal accounts but you would still have received email notifications about it.
If you have no knowledge at all then you might have to consider whether you have been hacked and whether this is an unauthorised transaction which needs notifying to your bank.
