How to complain

I'm not sure if there is a mechanism to report bugs via the iOs app - I can't find it on mine, which seems to be working fine otherwise. I've got an older iPhone SE running iOs 13.3.1. Let the Support Team know via https://support.chess.com/article/346-contact-us

I played a tournament. I was 1757 rated. I lost just one match and lost 11 rating points. Then after every match I won my rating got lower and lower and now I am 1697. What should I do?

That's not what shows in your archive.

I am winning the game by my opponent losing on time at the last but still every time my ratings are deducted is this a joke or what like I won but still didn't get any points

Examples ....or it didn't happen.

You abandoned the game...you lost.

i didn't abundant the game look at it carefully my id is RiddhimaUraon2005 i literally have 7 minutes

Game was abandoned, likely due to being disconnected from the live server.

https://www.chess.com/game/live/18558615067

Take a look; you never received black's last move.

Also, you're only allowed one account.

https://support.chess.com/article/596-can-i-have-multiple-accounts

I never received black's last move because he was out of time which is the main problem i won by my opponent losing on time and that account is different that is of om father look carefully i moved my knight waiting for his move but he reached out of time so who was supposed to win ?

Your opponent had 7:32 seconds left. You were disconnected for that time. You made your move on the client but the server never received it since you were apparently disconnected. Since the server never received your move, you lost.

If that is your father's account, you should not be playing on it.

first of all my fathers id is RiddhimaUraon2005 and he is the one with 7:32 min look carefully again and he plays on his mobile what made you think i am playing for his side my account is different my father didn't know how to complain so in his behalf i complained to chess.com team look closely please or get a eye test 

The Live Server is the only thing that matters. If the server does not receive your move, it does not matter what shows on the client. Your father lost the game due to abandonment, probably from being disconnected.

This is the final and only position that matters:

The other player had 7:32 on the clock and your father's game was counted as abandoned at 6:11 (at least 1 minute after being disconnected). On the client side, when it saw the time run out for his opponent, it forced a reload of the game and loaded the actual result from the server, which was a loss by abandonment.

yup

Dont do anything cuz ur rating didnt get any lower when u won ur games

ohh thank u in his phone it was showing the opponent have lost on time therefore i had a confusion sorry for troubling you 

Send a report to the staff. So far I've had no abusive opponent's at all. But in your scenario you could either number one, send a witty message back to your opponent that will hurt they're feeling's that much their brain will weaken and they'll feel bad about themselves, and probably lose the match if the material is equal, or if you're winning. Or simply disable the chat and carry on playing. Also then add that person to your block list. 

میخوام از کاربرانی که تو بازی تقلب می کنند شکایت کنم 

https://support.chess.com/article/209-how-do-i-report-someone