Star Bazaar — over charged , above mrp

Address:

Pune, Maharashtra, 411027

This is for New Sangavi, Pune Star Bazar outlet, i bought few items along with Parle Hide& sick and Cadbury biscuits, the store charged me 50 rs for Hide and Sick and 30 rs for Cadbury biscuits, the MRP was 30 rs and 25 rs for each item, when i went to home i doubted the bill amount and cross checked, i then went again to store and complained about this, the store manager Sandip Pal was arrogant to reply and corrected the bill and refunded me 25 rs back. However store manager refused to register complaint, and even refused to give the area manager contact details .
Please take this note and give me justification on why the outlet is overcharging to customers above MRP .