I'm going to refuse to sell to someone because they didn't follow my sale rules even if they were probably pointless
Do you really care about your sale rules? Is that the only reason you're against selling to this person?
I told them we have a policy and they refuse to follow it.
It is good to follow the rules. However, you should be able to be a bit more flexible when selling things to people to make the sale.
Idk, I feel like the rules are fair.
If the rules are fair then people should be expected to follow them. But it can be okay to make exceptions every once in a while if the person has extenuating circumstances that prevent them from following the rules exactly.