Daycare and Diaper Rash

My LO will be 1 in a few weeks. He has been registered to attend daycare 3 days a week since Sept 1st, but he has only been there maybe 8 days total. He was out with a cold for about 2.5 weeks. The rest of the time we kept him home due to severe diaper rash. Every time he goes to daycare, by the second or 3rd consecutive day he has an awful rash. It takes us about a week to get his bum completely healed up, but then when we send him back to daycare he gets a rash again. It's a viscious cycle.

We provide the diapers, wipes, and diaper cream. He does have sensitive skin, so we have told the daycare multiple times that he needs to have diaper cream lathered on at every diaper change. If he doesn't have diaper cream, he will quickly get a rash when he has a wet/dirty diaper. I completely understand that they have multiple kids to take care of, and it is impossible for them to catch a dirty diaper right when it happens every single time. Especially when my LO has sensitive skin, I get that a rash is going to happen sometimes. But I honestly don't think they are doing diaper cream like I need them to. Either that or they are letting him sit in dirty diapers for too long. He also has come home in diapers that weren't his (they were a different brand). So I am not sure how often that happens and if it is a reaction to different diapers.

I am at a complete loss. I feel so bad that my LO keeps getting such a bad rash, but I also don't know what else to do about it. I can't change daycares because it is the only place in the area. We can't afford a personal nanny. Is constant diaper rash just a necessary evil of daycare? What else do you think I could do to get them to take better care of his bum, if anything.