Sounds like you have either wires touching, or, if it didn't do it right away, the solenoid is stuck. In an oversimplification, the small wire on the (S) terminal on the solenoid energizes a plate inside the solenoid pulling the fork which throws the bendix gear to the flywheel and the plate makes contact with the battery cable (the top big lug) and the starter connector (the bottom big lug. A quick test to see if that plate is stuck is to disconnect the wire going the the (S) terminal, probably a purple wire, and connect the battery. If it cranks you have a bad solenoid. If it was old, it's a nut and bolt fix, but you paid for new and I know from experience that the folks at Summit will make it right.
Try the test and let us know. We are here to feel your pain and give you advise that is worth what you are paying for it. Tongue firmly in cheek, we really love to help.
