Synchrony Financial Credit Card Complaint

Synchrony Financial Credit card department,

Rewards Georgia

1 ) -/-/2016 I am supposed to receive my rewards check for over $670.00. 2 ) I never got the rewards check, and when I called the back they told me that the check is already cashed. 3 ) I opened a complaint and working with them for Synchrony back for 4 months. 4 ) They keep telling me that they have mailed me a copy of the cashed check for me to confirm the signature on the check. I never receive that also. 5 ) The custermer service is completely useless and rude and not yet solved my problem.