Don't give up, CTC's application process is only one application process to go through. Just because you don't meet their requirements (for any reason) it doesn't mean you don't have what it takes to become an airline pilot. CTC tell you this themselves on the website.
If CTC won't give you any feedback (they don't generally unless you are asked to re-apply) then self-analyse your performance. In the interview, did you notice any areas you were weak in? In the team building, did you play as part of the team? There are plenty of questions you can ask yourself to help you next time.
Pick yourself up and stick at it!
