Reading your monthly statement is absolutely necessary. Errors in totals charged to your card, charges added twice and other mistakes can add up quickly.

How to Register Disputes
If you find a mistake on your credit card statement, you have 60 days to contact your credit card company to complain. The credit card company then notified the merchant. The merchant can either do nothing and allow the disputed amount to be refunded to your account, or he can claim that your dispute should not be honored. When this happens, the credit card company gives you a chance to provide more information, and then makes a decision as to whether or not to honor your dispute, essentially acting as an arbitrator to decide which side is right. However, the result is non-binding.

Unauthorized Use
Credit and charge card fraud costs cardholders and issuers hundreds of millions of dollars each year. Identity theft is the most obvious way in which an unauthorized charge might appear on your credit card bill. However, your credit card statement might show a charge from a merchant who bills your card for more money than you've agreed to pay them.