if he cancel the summon, they breach the contract. And the lab cannot use his clone again for the experiment, MC could willingly to re-summon but not sure breach contract will do good for business while it isn't mc fault.
Sometimes it feels like the author is forcing him to be a bad guy but somehow he is forced to commit good deeds or is misunderstood. Like instead of genuinely trying to trick the devil he just wanted to get out or submit to him however his quest didn't allow him to. It really makes him to be an asshole