When you call your credit card company and make a dispute with the credit card company about charges the credit card company will then start an investigation which can take up to 3 months to determine whether the money should be returned to you or not.
The company that you paid money too through you card will then dispute the charges too with the credit card company.
You'll need to have proof that you didn't receive the product or service in order for you to win the dispute.
If you get your money back then the company that you bought the product or service from will have the money taken from them plus around a $20.00 charge back fee.
Before disputing a charge on your card be sure to contact the company you bought the product or service from and see if they'll rectify the problem.
Most companies will rectify the problem and/or refund the charges to you without you going through the credit card company.