I think it's great that you feel it's important to breastfeed and that you're doing all the work pumping. It's hard work and I'm proud of you for sticking with it. Unfortunately, I think a lot of NICU doctors and nurses just think it's easier to bottle feed so they push that, even if the evidence shows that breastfeeding is better. Unless your baby has allergy problems, he should be able to digest breastmilk just fine, it's the best food for a newborn! You may have to be willing to fight a bit, but if you stick with it you may have great success. (I'm a nurse myself so I'm not badmouthing doctors and nurses, this is just my experience). Ask to speak with a lactation consultant and an occupational therapist who specializes in infant feeding (preferably one with lactation experience). Let them know how strongly you feel about this and let them know that you at least want to try breastfeeding before your child goes home. It can be done!
My sister had a 27 week, 2 pound baby last october. It took months before she was even offered a bottle. However, my sister was diligent about pumping and really wanted to breastfeed. It took a lot of hard work on her part being available to nurse when the baby was ready. She had to watch to make sure the baby wasn't too overwhelmed. Slowly over the time she spent in the NICU (3 1/2 months) the baby figured it out. The doctors and nurses started to push her at the end to just do the bottle, but my sister stood her ground. Finally when she came home they worked on breastfeeding more and more. For quite a while the baby took a few bottles a day, but for the last three or so months the baby is exclusively breastfeeding. My sister is so glad that she stuck it out.
Hang in there and remember to stick up for what YOU want to do. It is your baby and you know what's best. There is no harm at all in at least trying, so they should be willing to let you do that. Good luck!