I am unaware of any State requiring a grace period for the instillation of services like Direct TV. (Or Dish) If you find a specific State law please post it.
You might be thinking for the law some States have about Door to Door sales, or for very specific sales such as Discount Buying Services, or Health related such as for use of Workout Studio. Direct TV is not Door to Door, even though you may be signing the contract in your home. That does not constitute Door to Door. (A possible exception - the authorized seller for Direct TV has no place of business where you could go to their office, it's strictly they come to you.) As with most any Contract if there is Fraud or you were mislead you can cancel, but you must have more than verbal promises or claims in most any case.