My WP will expire on 28th Jul. and my extension of stay will expire 18th Aug.

I think i will make Non Ed next time.

Do i have to cancel my Non B visa(or extension of stay) and WP before leaving country?

or if I just wait till the date when visa and WP will expire, then they will be canceled automatically?

My plan is leaving country for ED visa on 18th Aug.

Will be there problem? if I will go to airport without cancelilng WP and Visa.

Thanks in advance.

As your WP expires on 28 July, that is when your permission to stay ends, not 18 August.

You should get a letter from your employer stating your last day of employment, (28 July) and leave that day. Though the airport may not ask for the letter, many of the land crossings do.

Thanks for answer !

Have a nice day!