Deduction under section 80d for senor citizen

I am a Senior citizen. In the AY 2018 2109 IncomeTax Return, I had claimed decuction of Rs 28000 under Section 80 D.

For Senior citizens deduction of Rs 30000 is allowed. However in my case, Notice under section 143(1) was sent to me allowing Deduction of Rs 25000 and Tax demand of Rs 980 was made which I have paid.

How to get Refund of  excess Tax paid? (Rectification Request allows correction in ITR)