Section 51. An auditor may notify a person to whom money is due from the town that a certain designated amount, which may be either the whole or a part of the money so due, is payable to him upon application to an officer named in the notice, and, unless payment is refused upon such application, no interest shall accrue on said designated amount after the giving of the notice. A part payment authorized by this section shall not affect a right of tender, lien or other provision of law for the recovery of the amount of the debt, or interest or costs thereon, remaining due; but if the part payment is more than the debt as finally determined, the excess, without interest, shall be repaid to the town.