Walmart review: online pickup, being out of stock shredded cheese

So this morning I placed an online order to be picked up between 4 & 5 PM. At 410pm I received a text message saying my order was delayed. I was given no time as to how long. I called customer care & they found out for me. At 525pm I was finally notified by text my order was ready. I was unable to check in, I parked in a spot & after 10 mins a lady came to my car asked my name & stormed off. When she finally came out with my order she told me everything was correct. After I questioned her about my substitution she said oh yes that's correct. Then I asked why I was not given a substitution for my shredded cheese. She told me they were completely out. I pressed the issue asking how they could be out of all shredded cheese, she said we were busy & stormed off. To me that is poor customer service considering I asked a legitimate question & was given a bogus answer. I honestly think if you cant do your job you should be fired. And my spouse ended up going in the store & it did have all 3 types of shredded cheese I had placed in my pickup order.