@Khun *****
The links to relevant laws were posted many times here by me and by others, but the content just is not accepted by you and your friends because you don't know how law works, or think the truth is inconvenient for you.
When a visa is issued for a specific purpose and IO checks and denies entry because you don't comply to that specific purpose at moment of entry, any judge would agree with IO.
The fact that nowhere in law explicitly is mentioned that the requirement is not only valid at moment of application but also at moment of entry does not mean it is not anymore in place after granting application, because it is not mentioned in law that the requirement is lifted at any moment.
Everyone with some intelligence should understand that visa requirements are meant for during your stay in Thailand.