I have three children and all of them did this. I'm not saying your situation is the same, but I'm telling you this has happened to me. All of my children have done this. I would try to wake them to eat and they WOULD not wake. They each would sleep through feedings a few time'sand it startled me, cause with my daughter she slept 6 hours at not even a week old. I was enjoying the sleep cause she normally woke me up to eat. I freaked out and tried to wake her, and she acted like I was disturbing her nice little sleep. She went on to do this many times, as did my two sons. The doctor assured me it was normal, sometimes they just want to sleep. LOl. I am not saying this is the case with you, and by all means get the DR's help, I just wanted to maybe help you buy letting you know it has happened to others. Good luck and I hope all is well. And I'm sure the DR's aren't ignoring what you came in for, they are just looking for other symptoms of what "could be"

Doctors have not ignored that the child is sleepy. they are trying to find the cause why your child is sleepy. if they find the cause than only they can treat.