Hi Adele,
I agree that Mr A may have some basis to be able to claim his rates payments back, but I don’t think interest would be payable.
It sounds like Council issued the rates in good faith based on the information it held, and the amounts were paid voluntarily.
I think I would respond by saying that, under the circumstances, you’re not aware of any legislation that would entitle Mr A to a refund or any interest payment. If they consider that he is, I would invite them to particularise their contention.
It would be simpler to consider the basis they put forward for the claim, rather than to come up with a defence to the general request from scratch.
Cheers
Ian