I was also unsuccessful earlier in the year (a fair bit earlier than you actually)
At the time, I seem to remember a heck of a lot of people were going to CTC for Selection Tests, and quite a few (like us) didn't make the grade.
You're the first post I've come across regarding re-application. They did say that they would email you if you were suitable - I never received an email either.
It's been nearly 12 months.
Once I've got a spare minute between now and graduation in the summer, I think I'll just apply once again anyway.
They might not even notice!