Similac Check Question

We've been using Similac checks at BJ's for a few months now, it's the best deal for us. BUT today there was a 'new woman' at the register, so she bought the customer service guy over who said the rule was to only use one. In the past I've used all of mine no problem, this was the first I've heard of it. He eventually just let me put them all through since I've 'done it in the past', but said it's store policy to only allow one per transaction. He said same goes with Walmart, Target, Cosco and so on. Is this true??? Wondering why I've never had a problem with it before. HM. 🤔