I used char to try but I didn’t realize there was a limit , I have 5 chars at the moment, when I want to try the new class destroyer, I realized that there is a limit.
I don’t think anyone can do anything for you, you used up all the Knowledge Transfer charges and that is it.
If you want to play a new class, you’ll have to level it up from scratch or wait for the next powerpass.
As far as I read, they want to have a limit for us to open new chars and farm t1 materials, that’s why they brought this system to keep the market in balance.