American Express Membership Rewards - Avoid paying amex point reinstatement fee

FYI: Amex has an unwritten rule that if you do a lot of charging on their card they will reinstate at no charge points that had been forfeited in any particular month.

You don't even have to charge that much. Just call and ask and they do it once or twice. Don't make a habit of it and you can keep doing it. Make a habit of it and they'll charge you the fee.

So, if you have several months (one here, one there) of forfeited points, will one reinstatement fee cover all months, or do you have to pay the fee for each month?:(