I think the store could have any policy they choose about writing a check for over the amount of purchase. It is a courtesy extended to the customer. They are not a bank.
You got what you wanted on sale. I don't see the problem.
Ding! Ding! Ding! We have a winner!
Cash/credit customers don't have this purchase restriction.
I don't patronage Kroger's these days anyway. They have a "discount" card that gives buyers the same prices they used to get (now they just gouge "non-member" customers) and only have "self-checkout" lines (again, no discount for making me do the work that someone was paid for). There is still a cashier who must finalize the purchase.
I prefer to go to a business that doesn't gouge some customers and get them to do the employees' job for no cost savings.