105-107 is fine. Truly, the breeder should have kept the baby until it was fully weaned. You have to understand one thing, many breeders will let go at unweaned ages to free up their personal time of having to take care of babies. When you remove a chick from the rest of it's clutch mates it can be stressful and lower the confidence without the company of the other babies... which, at feeding time when one begins to beg the others follow suit and will also beg. Trigger response is greater in a group of hungry babies. Are you using a syringe or spoon? Are you in a well lit room? Sometimes dimming the lights to low will help as young ones at this age do recognize the same person that's been feeding them ( the breeder) and may not want to feed from a stranger in a new and strange environment. What are you keeping this young one in?
Exactly when did you bring it home? If it isn't eating any formula, not enough of pellets to sustain health and weight call the breeder and ask to bring it back for them to finish the feeding until it no longer accepts ANY formula. Just be honest and tell them you are fearful of taking care of such a wee one and would prefer to let them take that responsibility. It doesn't take long for these tiny beings to go downhill.... don't wait.
Lastly, hand feeding yourself does not mean a bird of any species will bond better to you and can often have negative results.