Sounds like a pretty simple software code change to me, Don. If your bureaucratic system is anything like ours they will have same sex entries sorted in a couple of years but will not have set up any software coding to enable couples like you and Tom to - easily - reclaim your overpayments. Presumably when it is all sorted out they will pay you interest on the amount they have overcharged you and Tom - Oops, that's more software coding isn't it?
Keep your fingers crossed for a quick resolution (but don't hold your breath).
Ken.