How to get referrals for a graduate job at MBBs, coming from a non-target university?

I started reaching out to consulting since I was in first year and have been reaching out till now (In my third year). Often what happens id consultants do give advices they are ind and help you out, even compliment my resume but when I approach them for referral they start ghosting. Some even don't ever reply, some say I will and then ignore forever. I just don't understand the reasoning behind this if someone's resume is better than you have seen uptill now then why not refer them and let them show their capabilities. One consultant that referred me gave me this advice to never feel bad about asking for a referral because they get rewarded if you're hired but it doesn't seems like many consultants nowadays are willing to refer candidates.