Check around. I know that some of the "chain" vet offices in my area are offering discounts on shots. Also - check your local shelters and big box pet stores. I know that in Michigan, some of the PetCo stores have once a month shot clinics. Check around with some local rescue groups. They may know of some place you can get some help.
Don't give up your puppy unless you absopositivitlutely have to.