Recertification of propane cylinder

Refilled a 20 lb tank today and was told it expired this year. The attendant said it could be replaced with a new tank or recertified. The tank is 12 years old and in perfect condition. Recertification is good for 5 years but I can't find anyone to recertify it. New tank is around $30.00 and won't need recertification for 12 years. Sounds like new is the way to go. Has anyone recertified a tank?

Bob