what happens when you exceed your credit limit
Normally, if you go over your credit limit, you will not be able to use your card for purchases again until you have paid an amount sufficient enough to bring you back under your credit limit. Also, most (if not all) credit card companies will charge you an over the limit fee for exceeding your credit limit.
You'll be charged penalty fees. If you exceed your credit card limit, you can expect to see a special over-limit fee tacked on to your next monthly statement. TD Canada Trust charges a $25 over-limit fee, and so does RBC Royal Bank. Scotiabank and CIBC's over-limit fee is $29. Not all cards charge these fees, though.