Builder won't correct Form 26AS entry after weeks of followup

My mother's flat is being redeveloped and the builder has incorrectly adjusted a portion of the hardship charges against additional area and shown it in her form 26AS. However, she has not availed any additional area and this may also be an honest mistake. After weeks of follow up with the builder, there has been no resolution on the same. I've raised a grievance with CPC-TDS but can you suggest any other form of recourse to get this corrected?