I like Walmart and I shop there even in defiance of our companies founder, Who can afford to shop elsewhere. I can not!
Walmart's policy of not counting you arrived at the gate is equivalent of ordering a pizza with a guaranteed 30 mins or free and then giving the delivery guy the run-around when he buzzes to get into an apartment building and tying up the elevators so they can not possibly get to your floor and then calling them late because they were not at your apartment door within the 30 mins so you can get a free pizza.
Impeding access at the gate to the check in is a Walmart problem not a delivery problem.