I WANT TO CANCEL MY EP APPLICATION

So, you didn’t see all these issues before agreed and sign the offer letter with Company B? You can request Company B to withdraw the EP application. They have every rights to complain against you at MoM.

Before agreed and sign the offer letter, it’s your responsibility to read through and understand the differences. You simply can’t say this after an employer put an effort to process your work pass.

MoM won’t have an issue till Company B complains about you. Good luck

You signed an employment contract with company B, which you must fulfill (incl. any termination notice period). If you tender your resignation now and can keep the notice period before you actually need to start work there, everything is fine and company B will cancel the EP application. If not, you would have to break the contract, giving company B all rights to lodge a complain with MoM.
Note: Company A can now see (in MoM's EPOnline system) that another EP for you was applied for. Some employers put such disloyal employees on an "to be fired" list.

Thank you for your reply. Actually I didnt sign any contract yet with company B, they just email and offer a salary and through phone call I agree. Recently,  my EP of company B approved already and I want to turn down the job now. I ask about the contract they tell me that its not ready yet. They will let me sign the contract few weeks before my starting date on which its very strange. What do I need to do now.?

A contract can also be agreed on verbally, as in your case here. Of course that makes it more difficult to enforce, which now works in your favour. Just inform company B that you are no longer interested in joining them - and see how they react. Stay cool if they get angry - the worst they can do is complaining to MoM, which would not affect your current EP with company A (but it might affect future ones, so don’t try to change again for a few years!).

Thank you. Till now I can not sleep. On that matter do I neet to site reasons why am I not joining them?

You don’t have to give reasons, but you could and it might help to keep them less angry. (Not the reasons you gave above, though!)

I strongly believe that there must be exchange of mails on both side about the job offer and agreed on it’s pre & post conditions or benefits.

I don’t think someone spoke over phone to a potential employee then agreed to apply EP for him or her without any written consent or agreed on email. At least, not at the present environment.

You should approach Company B asap, we had discussed on Sunday and by this time you must have spoken about your intention to them.

Now, it’s already late but not the end point, start approaching and negotiating with them to withdraw your EP. Company B has every rights to complain at MoM (because MoM will ask them why are they withdrawing the EP after approval and they have to give a valid and solid reason for that - MoM doesn’t like these kind of applications).

Now, I’m scared Company A HR can see another approved EP is under your FIN number, which will creat negative impression at their end and they may inform to line manager too, if they wish. Good luck