Whenever you use your credit card, the transaction is first authorized before it's billed or posted to your account. Authorized transactions that haven't yet been posted will stay on your account for about 7 business days. This is how long it takes the merchant to finalize the transaction. If the transaction isn't billed within that timeframe, it's automatically deleted.
If the transaction amount is wrong after it's been billed, the first thing to do is to contact the merchant to try to resolve the matter. If you can't come to an agreement, then call us at 514-224-7737 (514-CAISSES) or at 1-800-224-7737.