if I've created account/wallet on coinbase or any other exchange then my account is hacked and my coins/money lost who are responsible for it
The Exchange where I've created account

is it my mistake

what's you thought about it

and how i make my account safe

Losing money or coins is something everyone doesn't want. You must confirm with the Exchange team on which you are registered. If they do not respond, I think you have not been lucky. With such incidents can be a valuable lesson for you. For the next, you have to trade in exchange which has excellent security.