Why, they are going on ?

"WCC_SURYA may have violated our Fair Play policy - it has been noted and they may have their account restricted."

chess.com gives above message. you saw it .but nothing changed . he / she continuee normal games . their account do not close ! why is that ? you know that ?

May have violated is not definitely violated.
Account restricted is not account closed.

A player may stop moving in a game due to a bad connection for example.

thank you binary code

anyway , I still do not understand that Why this has not done to me in 9 years  in chess.com :)

 Wow 9 years

I don't know. Maybe the fair play rules didn't exist many years ago?

I do know that now there are more people playing from phones and other wireless devices. So maybe now it is more likely for you to play opponents who disconnect.