The same thing happened to us. We had a 3 small charges (for $.06, $2, and $4) to test and see if our accout was open. Then there was the $79.90 charge. We called Band of America after everything had posted and they are removing the charges and filing an affadavit. This happened shortly after my husband entered his credit card number to make money filling out surveys. He didn't know any better. Don't ever do that! Those things are a total fraud and they should never need your credit card number anyways.
Just call your bank. They will fight the charges. And make sure that you don't have the other small charges too. Most likely you will. They do the small charges up front to make sure that the account exists. Make sure that you have your bank remove the small charges too! Don't give these crooks a single cent of your money! That's what they count on- either you don't notice the charges at all or you forget about the small charges because that adds up for them if they scam a lot of people.