Here is the latest email I received from MS today:
Hello,
Thank you for contacting us regarding your Live Search cashback payment.
We have encountered a technical issue while processing some payments for recent eBay cashback purchases. We are actively investigating the root of the issue, in close partnership with eBay and PayPal, and are working to resolve this as quickly as possible. We'd like to assure customers that all eligible cashback payments which meet the Live Search cashback and eBay terms and conditions will be rewarded. We apologize for any delays and thank you for your patience. As soon as we have more information on the resolution of this issue, we will be back in touch.
Sincerely,
Wyatt
Live Search cashback Support