Good service, unsure about the products

I bought nestle Nan 900g starter formula at Game Groblersdal, the label on top is written 2 and the label on the tin is written 1, I took it back to check what could be the problem. I discovered the last tin in the store had 9 numbers as the batch number and the other and the one I had bought has 10 numbers. The manager was willing to exchange the product but then the batch numbers had me unsure I decided to return the product. I thought of changing formula but then I compared products at clicks and they all had 9 numbers on the batch now I’m really unsure.