Reliance Fresh — frequent instances in difference in price tagged and pice billed

At Reliance Fresh at Aundh, Pune 411007 on 90 % of my visits, I have observed that I am billed more than the price tag displayed on the shelf.for some of the items purchased. On complaint I am informed that that employee forgot to update the the price tag. It seems that proper care is not taken by the employees. To quote particular instance, on 14th March 2015 at 18=30 hrs the price for green grapes was tagged at Rs 18=75 for 250 gms, where as the item was billed at Rs 20=00 per 250 gms. Such instances are frequent at this location.