Others have given the same advice I would. I will add an additional aspect to it - your pact may not be accepted. You may be offering too much for too little or the opposite. What you’re asking for may already be coming your way and the offer would be too lopsided. They could reject it for any reason at all and if you don’t have someone (preferably yourself) to negotiate for your desires and make it worth their while, it could be rejected outright. The person you hire may not relay this or may not be advanced enough to understand what’s going on. None of this would help you.
But if they did the pact for you and said it was accepted (when it wasn’t), you’re stuck with upholding your end for no benefit.
Simple English Demonic Evocation Guide - New Magician Help & Introductions - Become A Living God