You absolutey should, and should be able to, dispute it. Find out where the charge was placed and provide evidence that it wasn't you or your husband, based on where he (and also you) were at the time (e.g. if the charge was from a different city), your spending habits vs. the type of service or goods bought, etc. If your husband was on deployment, there may be veteran's support groups and/or services provided by the military for military families that can also help you dispute a fraudulent charge.