Question for the forum....which lead generation companies out there are the most credible? Looking for the equivalent of the CAN, On Deck, BFS type companies versus the stacking, c,d-paper companies.

All of my experience with lead generation companies are the following....get lead sent to you, call lead, have merchant complain that their phone is ringing every 5 minutes and i'm the 15th company whose called him, then he proceeds to tell me he hasnt even started his company yet.

Appreciate any help