Is it time to quit

My boss is walking all over me...I requested off a few weeks ago and told him way ahead of time that I would be out of town and that I already had the hotel booked and all and he still scheduled me even after he confirmed that I had it off in person and over text and those texts also say “as long as your days are in the request off book you will get them off” but he has done it again I took off for tomorrow and he scheduled me yet again and I told him I could work another day he gave me off instead or whatever he needed and he flat out avoids the situation and I’m debating on calling off but I’d also like to just quit they don’t pay enough for what we have to deal with anyway... any advice?