Truly does suck you just bought it, but it should have been free already, along with everything else that came with AoD. AoD feature expansion was a terrible idea 8 years ago. It probably should have been slapped with DoV part 2, but SoE didn't want us buying DoV more than once I guess. Nearly everything in that expansion was too overpowered to ignore but it wasn't even a real expansion. It makes sense all the things in AoD should be free now since some of the features aren't even around anymore or are forgotten and ignored. Are mercs free yet?
The merc feature is free with the purchase of any expansion after KA and was included in the premium edition for KA.
You can probably get a DBC refund by mentioning the change in a petition. I've had about 3-4 refunds on EQ1 and Planetside 2. Daybreak CS is pretty good about refunds if you explain the circumstances.
Meh, it's just 1000 DBC from the last two months of membership. Not like I'm saving it up for anything bigger.