gooh said:
What if my credit card has a limit of 500 dollars?
You can pay with someone else's credit card. It doesn't matter the name on it. This is what I recommend.
If not, your only other option is to order the immigration receipt and wait for it to be mailed to you, then you have to take it to a bank in Canada and pay.
You will have to look up he receipt needed and how to order it. I paid online, as most people do, and so don't know the specifics of ordering the necessary receipt to pay at the bank.