He is most likely getting the infection because someone is trying to retract his foreskin before it is ready. This tears the connection between the foreskin and the glans slightly, and allows the infection to happen.
Your doctor has the wrong information...and the wrong attitude. No one should retract a foreskin on a child, unless it is the owner.
Your son doesn't need a circumcision, he needs a doctor who knows basic human anatomy.
He should sit in a warm bath, with the foreskin left alone, to relieve discomfort. The antibiotics should take care of any infection.
His foreskin will retract in its own time. That can be anytime from birth, to puberty, or even later. If he can't retract as an adult, simple stretching will fix it, or simple stretching combined with betamethasone cream. If you want more evidence about when a boy retracts, do a web search for the Oster study....Oster + foreskin should do it.
There are valid reasons to circumcise. Frostbite and cancer of the foreskin are two of them. Your son's situation isn't even in the ball park.
Been there, done that, with the medical professionals. We had our first son circumcised due to incorrect medical advice. The second son, we left alone, and he has been problem-free for 28 years.