We paid ours and we did ask about it, why etc. we were told that if you have a tapu you have to pay. Even if there's 20 apartments on a complex, each owner has to pay. We could haver chosen not to pay, but we'd have lost the 1/4 off and so thought that we may as well pay. Pretty cowardly, but the council tax had gone DOWN and didn't want to keep getting asked about it, accruing interest etc so paid. It did take rather longer than we'd thought though.