Redeem Code 'RAMADANKAREEM' issue

Yesterday I tried redeeming the code 'Ramadankareem' but the page showed error that due to high volume of people process cannot be completed and to try again 10-20 min later. 

But when I tried to redeem the code after 2 hours the site showed that the code is valid for single use per account and the code has already been redeemed but when I checked in game I didn't receive my rewards. 

Kindly help me plz