Okay, how do you ask for the canter in the first place?
If you make sure that he has a quiet, balanced trot going into the canter, then the canter should also be quiet and balanced. Don't let him lurch into canter or run into canter. If you don't get a canter transition when you ask, and he just speeds up his trot, then bring him back, get his trot balanced, and ask again.
A balanced canter in an arena is much harder than a canter out on hacks, so don't ask for too much at once. If you can get a few strides of nice canter, go ahead and ask for a trot again and praise muchly. If you ask for more canter, he may lose his balance and go "crazy" again, so just ask for a few trides at a time.
Getting a good transition and only asking for a little at a time sound like easy/short duration solutions, but these are actually quite difficult. You could spend days, maybe weeks, on getting this right
So try it for a while, and hopefully you'll start to see someprogress from him.