From what I have read, never having had a new bottle baby, so take this with a grain of salt... I did get two wee girls at one time that were on the bottle, but I only had to bottle them for a couple weeks and at that point it was super easy.
Feed no more than 20% of the kid's weight in any 24 hour period.
Week one: 5-8 bottles/day
Week 2-4: 4 bottles/day
Week 4-8: 3 bottles/day
Week 8-10: 2 bottles/day
Week 10-12: 1 bottle/day.
Bottle babies will always act hungry because they want to suckle. It is an instinct. I let my babies suckle on my fingers when we are doing lap time... if they want. Just watch out to not let them bring your finger to the rear of their mouth as that's were the molars are and even a baby chomp can hurt.
So, it sounds like you may have been feeding too much at the start. Check their weight now and adjust the amount if you need to.
You don't say what you are putting in their bottles. Whole cow's milk is just fine. Warm it up and they will slurp it down. I don't see the need for fancy milk replacers, but really, truly, that's just me.
How is their poop? Is it nicely formed berries? Are they peeing frequently? In other words are they acting like rambunctious goaties?
Please keep us posted on how your girls are doing.
Oh, one more thing, when you get a chance would you please put your general location in your information so it shows with your avatar? We don't need your address, unless you want to host a party, but the general location is helpful in giving advice. What works for me in North Central Texas may not work for you where you are. Thanks!