Property Tax Refund Error by City

What is the name of your state? new hampshire

i own a home in manchester, nh. last month i received a check from the city with the description on the stub as "tax refunds" (pertaining to my property taxes). it also stated "not negotiable". last week, i received a phone message that the check was sent in error and that i need to return the money (i had already cashed the check). i did not receive anything in writing. today, i received another phone message stating the same as before and that interest is being accrued on the money due. the message also stated that this amount will be included, in addition to my new property tax bill being currently mailed.

am i liable for this money? or is this error the responsibility of the city? again, i did not receive anything in writing regarding this matter, just two phone messages, and now my new property tax bill is going to include this 'refunded' amount also. if i am liable, does it include the interest (since i did not receive anything in writing). thank you for any help you may have.

You're liable for the money, but you might be able to argue that they cannot charge you interest without a written agreement, or at least a written demand on county letterhead for repayment. This could be a new scheme to bilk people out of money. After all, you don't know if the person who called you works for the treasurer's office.