Need advice...

I am currently a SAHM to a 2 year old. To help with some bills, I offered to do babysitting out of my home. I’ve been watching this 3 yo Mon-Fri since the end of June. The problem I’m having day after day is he doesn’t listen to anything I ask him to do/not do. It’s not like he doesn’t listen because he doesn’t understand, he just blatantly doesn’t want to listen. When I ask him why he did something he laughs at me and replies “because I wanted to”. I bring it up to his mom, everyday. Nothing has changed. It’s the same thing every single day. Behavior charts don’t work, time outs don’t work. I’m at a loss as to what I can do. It stresses me out so much, i dread the next day. I need advice on what to do. It’s not that I mind keeping him, I just can’t have him disrespecting me and everything in my house. There’s a difference between being “all boy” and flat out disrespect.