Visa Type : WORK-YEARLY VISIT (Single entry)


One of my friend has an issue where he got the offer letter  for company1 and he did not travel to Qatar yet on his "Single Entry work Visa".

Recently he got a one more offer from company 2.
Now the issue is If he rejects the company 1 offer, can they cancel his workvisa? or If yes how much time they might take.
Or while Company 2 processing the VISA they would not get any VISA issues?

Would be great help if you could help on this.

Thank you...