State insurance laws and insurance company guidelines may differ but normally policy rates are not increased or decreased mid-policy or mid-term.

Premiums typically are not adjusted mid-term because of changes in a policy. For example, if you have a clean driving record when you start a policy and you are rated as such. Then, mid-policy you get a speeding ticket; your rates are not re-calculated at that point in time. Instead the rates usually will be adjusted at the time of the policy renewal.

If you rates went up immediately when you received the moving violation then it would seem fair that the premium would go down immediately after it leaves your record but typically your insurance carrier is not aware of the violation as soon as it occurs and you are convicted of it. So if instead your rates did not go up until the renewal period after the violation, when your AAA insurance company checked your motor vehicle record (MVR) and found out about it, then the same would hold true for the decrease.

You can contact your insurance agent to see if your provider does mid-policy changes in rates or not. As for state laws on a situation like yours, check with your state's insurance regulator.