Consumer Redressal

sir, I purchased two kwality walls icecreams with mrp rs20 in kwality restaurant, red light, gt road, panipat. The owner charged mrp rs 25 in the bill also taken vat on that.thus he charged sale value rs 50 and vat rs 6.56 and made bill amount rs 57.I objected that he should charge vat on sale value rs 40 but he refused and asked me to do whatever I can. sir it\'s my humble request please help me, so that people like me will not suffer again.