Walmart pick-up in store sucks..

This is super random to post on here but I was wondering if anyone knows why Walmart pickup is so unorganized.

So, I had a baby shower to go to on Saturday, and I forgot about it til Thursday, and I was going to be making some blankets and clothes for my best friends baby girl. I got out my very old sewing machine and of course, it is not working. So until I could figure out what was wrong with it I was going to buy and use one from Walmart.

I looked online, and there was a good deal on a Brother machine and it said available now or pick up in store today (this was on Thursday), so I bought it online and I planned on being about to pick it up late that day. Well the day comes to an end and I still had no update. My fiancé had ran to the store for some stuff and I told him to go check the sewing section to see if they were actually out of stock and maybe that's why it was not ready, and they had 3 in stock. So I figured it would be ready in the morning and I could pick it up.

Well in the middle of the night I got a text update saying my order had been delayed and the estimated pickup day is now 1/25.

Needless to say, I was a little irritated because I had stuff to make. So I put my face on and went to Wally and got the sewing machine took it to the pickup center and showed them my online receipt and told them the situation and asked if I could just take this one, and they got kinda angry and acted like I was telling them how to do their job and basically I was told I cannot take one from the floor because mine was already shipped from a warehouse.

So I had to drive almost 2 hours away to my grandmothers house to use her machine.

I'm just wondering if anyone knows why they couldn't and wouldn't pick one from the floor for pick up? Is there some rule or something? It was very inconvenient to be told it would be ready for pickup the same day and then told it would actually be there a week later.