Engine users

I'm not sure if some players here use the help of chess engines while playing. I feel so because at many games my opponent just plays around 15 to 20 moves inside 30 seconds and all are perfect. How is that possible without thinking for a while. If anyone has felt that they have been beaten by a engine. Pls troll those guys through this forum>

You shouldn't worry about that at all. Chess.com has software running all the time to detect engine use and anyone actually using engines would have a rating far beyond your current level.

When you think about such things it just distracts you from thinking about the moves you need to play.

Look at a position from your most recent game. How do you think you are doing here? Where did you lose this game? Was it owed to something you did or some engine moves?  

Your opening was very passive and you let your opponent easily achieve a huge space advantage. Later in the game, your opponent broke through with his pawn and was about overwhelm your poor lonely king when he blundered and dropped the exchange.

That gave you a second chance:

but within a few moves you were losing again. Engine use? Not at all. He figured out weaknesses in your position and went after them. You did nothing to stop him.

You have an engine sitting on top of your neck but you aren't using it.

Instead of worrying about something you can't control, you should spend your time looking at games like this to figure out what you could have done better.

you judge them perfect or an engine has found them perfect? 

peraphs I don't understand if he palyed 20 30 moves within 20-30 seconds it means you were also blitzing... there's a high chance you went wrong in the opening and he had only straightforward moves to play...
I'm not sure how fast you can go while usiing an engine but I doubt you can be close to 1 second per move, although it's just my guess. 

He might be running his chess engine in his mobile phone.so how can the Chess. com detect that.

It doesn't matter if someone uses a phone or a computer. Chess.com looks at the moves. If somebody plays whole games with moves matching the best choices that Chess.com's computer would use, it gets flagged. Anybody who uses an engine has a rating far above a 1300 level.

Look at that game I posted. That loss was Amruth's fault and nobody else's.

Yeah, the black allowed white to develop his pieces and white knight always wanted to come to outpost at nd6 and black allowed exactly that.