Costco review: pizza order and pick up policcy

This morning I went to Costco to buy a pizza and do the grocery shopping. I went to order the pizza first. I got in line, order a pizza and paid. The employee said that pizza will be ready in 20 minutes. After I done my grocery shopping, I went to pick up my pizza. The employee said because I am late for 30 minutes so they rollover(?) the pizza. I don't know what did they do for that pizza but I can't get my pizza. They want me to wait there for 15 minutes. I even heard another person after me need wait for 40 minutes. I asked what I need to wait? I got in line to order the pizza and I paid the money then they should keep my pizza. I don't care is my pizza cold; I just want my pizza is ready for me to pick up when I done my grocery shopping. If I buy the meat or fish that day how can I wait so long? The employee just answered me that is our policy we need to follow it. WOW! Who made this so ridiculous rule? After I paid, I think the 20 minutes should means that pizza is ready to pick up after 20 minutes not I need to pick up within 20 or 30 minutes. When the person made the rule they should consider about the customer is paid or only order by phone, and they should tell customer how long they will keep the pizza ? Also, 30 minutes is too short for doing the grocery shopping at Costco too. Another problem is they want me wait there for 20 minutes. Who is counting who wait how long? Like today there are more than 5 people wait there, 10 minutes later when I ask again, another employee said I need to wait for 20 minutes. WOW! That surprised me again! I got mad! They sent the manager out and immediately gave me a pizza. That's not right! I understand in Costco the pizza order and pick up is more complicate but please make a more reasonable, logical, and more efficient policy. I like Costco pizza. It's good price and delicious. However, when I order pizza there, it's too often had unhappy pick up experience therefore I am little afraid of order pizza there.