I'm sure you can obtain a copy of the certificate from the town hall planning department (urbanismo). You will probably have to submit a written request on a form provided by them (in Spanish) and there may be a nominal fee to pay. Do you have a representative in Spain to do this for you? Perhaps the lawyer who handled your purchase?
As for the boletins for the water and electric, the builder must have them. I don't know about the legalities of them handing them over - I would have thought they are obliged to do so, but if they're holding you to ransom over the non-community fees, maybe best to consult your legal advisor on this as well. Alternatively, you could try talking to the utility companies and explaining the situation. As it's a new build, they may already have copies of the boletins. I really don't know. Worse case scenario, I suppose you would have to pay for boletins from certified professionals yourself. For the electric, you're looking at maybe €150. Don't know about the water.
Hope this helps a bit. Hopefully someone else will have some more input.