Hi there. The error 717 is caused when the facebook and Chess.com accounts are trying to be merged while facebook account still has its two week free trial on it.
If you can message me the name of the facebook account to confirm, i can remove the diamond, you can then successfully merge, and i can re-add the remainder of time to the account (once you contact me to let me know the name on the merged account).
I took another look at the facebook integration, and now there's a feature to merge my chess.com and facebook chess.com accounts. Great, except I get this error message:
Error 717: This account is already premium. Not able to merge.