Years ago I was a sales manager for a Fortune 250 company. When I was interested in hiring a salesperson I would tell him or her that I was not going to hire them. If they gave up and left, they were not hired. But if they tried to sell me on themselves, I would hire them. I wanted a salesperson who would not give up when hearing “No.”  Think the same way when corporate buyers say no to your proposal. Consider that they are simply testing your belief in your recommendation. Continue by asking why they do not feel your proposal is right for them, then counterattack.