Seeking advice on if I should use referrals or not

Basically after some hardass networking I basically have a guaranteed referral from HSBC (possibly even two) one from IB another from WM but the person in WM is higher up than the person in IB so i dont even know which one would be better to ask for a referral. Also one at Citi (the person is in IB) and a possible (unconfirmed) one at jpmc. I already have one internship in DCM at a pretty nice firm and my technicals are pretty strong i would say. I am not sure what to do tho my grades are pretty much garbage as of now(I need to sit in three exams and also even the ones that i passed i have a pretty low GPA as of now but this semesters grade from my calculations plus if i do well on the three exams i have to take should bring my GPA to the grade that would be considered ~average/bare minimum for recruiting) but I know that I should get it to the minimum that I need by end of semester. So i was thinking do I not use these referrals and wait to raise grades or do i use these referrals? If i use these referrals now and dont get in anywhere i would assume that there is no way in hell the people would refer me again (can they even refer the same person twice?). I asked around and some people are saying not to wait and that it will be too late then and to risk it but some are saying that its just wasting a referral and it would be better to give it a shot right now. im really conflicted. Idk if it changes anything but im at a target uni. Yes the grades are pretty deflated here but when i say ill reach the 'average/bare minimum' for recruiting i mean for my specific uni i dont mean ill reach a 3.8 or something.