They should have gone to the property management company which is something the tax office could and should have been able to find out very easily.
We are currently in a small legal kerfuffle ourselves as the mortgage company underpaid the property taxes for several years. The taxes had been frozen but should have been reevaluated when the property was sold, something that was not caught by the treasury even though they were sent a proper change of title notice. Recently they elected a new treasurer who now wants us to pony up the back taxes that were never paid even though no one told us or the mortgage company the taxes had gone up.
Seems like the same thing happened to several of our neighbors who bought their property in the past ten years. It is going to be interesting to see what happens.
My county treasurer tried to tell me that one of my problems is that my mortgage is with a credit union that writes checks for each tax bill. She said they weren’t big enough to be qualified to be noted On the tax bill as the tax payer. (She used a fancy word but my mind isn’t fancy) So everything still comes to us and every 6 months I have to make sure the taxes were paid. It took a year to get it straight in the beginning because someone forgot to check the box that says escrow acct and no taxes got paid nor the house insurance. I think this home owns me.