You need to contact directTV and file a complaint, and then have them permanently disable pay TV from the account.
If you mean someone is charging the credit card for actual internet porn (rather than pay tv), it has nothing to do with direct TV and instead you need to file a fraud case through the local police station and have them give you the case number so you can forward it to your credit card company. Your card company will then issue a new card. At the same time, you should reformat all your computers because you may have a virus that skimmed credit card information.