Agreed.uh..backlinking services do just that ;create backlinks. its up to you to index them.
I never bought any backlinks (I'm strictly DIY now), but if I did, I would treat them like the backlinks I create for myself. I start creating backlinks for the backlink URLs using BMD, creating and and submitting phony RSS feeds or what have you, then pinging those new URLs.
If your are not into DIY then extract 1 or 2 thousand urls from the 70K and submit them to the same type of service and tell them to distribute 70K more backlinks among those URLs and ping those.
I'm guessing you'd want to limit this to just 2 or 3 tiers.