I have a local Gas station with Propane refill service. I have always taken my tanks to them in the back of the TV secured in the upright position and physically stood there when the attendant refilled them. (I know my way around such things servicing LOX bottles in the Air Force)
That said my Nu-2-Me '05 TT came with old, rusted, outdated tanks... I will be taking them to the zit faced kid at the local gas station / hardware store for exchange. They let me pick the tank when I say "I need it to look pretty for my camper" All the while I nonchalantly check the cert dates....
Caveat Emptor. AKA: there is more than one way to skin a cat.