24 q tds filling

Greeting I have filled TDS returns for Q4 of fy 16-17 for salary. The return was filled on time. Both the PAN No are valid. The firm has two employees who been paid a salary of 4.50 Lakhs each only in the end of the year. i.e 31/3/17 and TDS deducted and remitted for each is Rs 45,000/- same has been remitted within the stipulated time. On filling and processing the TDS returns, CPC has raised a demand on short deduction for 15450 along interest on short deduction for Rs 616 for each summing to 31,520/- Now my query is when i have deducted Rs 45000/- for each on salary of 4,50,000 for which payment was made on 31/3/17 where does the question of short deduction arise, when TDS has been deducted @ 10%. What steps should i take to rectify the same?