Reliance Mart — lion dates 200gm offer

Address:

590005

080450 ln sdd date 200 g pp 71.00
Sir
I purchased lion dates as buy one get one free offer.
At the cash counter i was not informed to collect the free offer
I thought they charge for one and give one free. So i picked two packs. He charged for two and silently made the bill without telling.
So please let me know further.
Attached bill for your reference.