Firstly, swapping their diet around can reduce laying until they adjust. It's best imo to make gradual changes to diet. So stopping the proper feed and just giving them corn isn't going to help, especially since corn isn't adequate.
Secondly I'm not sure if I'm reading this correctly or if this isn't what you meant, so forgive me if I'm incorrect- but are you saying that you stopped feeding them properly due to not getting enough eggs and not wanting to spend money on them? You need to make sure your animals are fed properly regardless of what they're giving you. Is selling eggs a source of income for you? Because if so I can understand your view especially with how pricy animal feed can be. But feeding them just corn isn't going to help. Their health will eventually suffer and you'll get even less eggs.