You are not being overprotectitive !
At most a doctor should only prescribe a second round of antibiotics. Your best bet is to contact your insurance company direct. As for the floor supervisor, they will see there is a referral in the system and tell them you want to see a Pediatric ENT immediately. If they tell you they are doing all they can you call the dr. office and ask to speak with the dr. themselves. You need to be adamant without raising your voice.
You can express your concerns (I'm not trying to scare you just give you some good wording to catch someone's attention)
scarred tissue with each infection, ruptured ear drum that causes long term problems, and you don't want his to develop into a hearing loss issue- ask what kind of speech therapy your plan offers. Mention, you have done the recommended course of antibiotics more than twice- FOUR TIMES ! This is absolutely unacceptable.
In the meantime, keep your child at home with you away from other babies (you don't want to give someone else thrush), make sure to feed in at least a 45 degree angle (if their legs are resting on your lap them their head should be resting on your upper arm. Start making a diet diary of what is consumed, how much (be accuarate don't guess) and at what time. Three weeks running log helps the dr. as well.
Finish out this last dose of antibiotics and refuse another round.
How rough for you and your child. I'm so sorry your healthcare professional has let you down. You didn't do anything wrong, your supposed to trust them to give you the best care possible.
"go get them !"