Am I wrong for feeling annoyed and frustrated by my dad because of this?

I (20M) am getting really annoyed at this point. I live with my grandmother who lives near her youngest child, whom which is my dad (40M). The reason why I am so annoyed is because he always asks me to come to his house only when he wants something from my grandma. He isn't disabled or anything like that, he walks perfectly fine. But for some reason he feels the need to ask me to bring something to him.

Before you say that I'm a horrible son, my dad left me and my mother when I was only a child. I still love him as much as I love my mom, but I don't want him to treat me like his personal butler. I do my absolute best to love him, but I'm getting annoyed and tired of him only reaching out to me whenever he wants something. I want to scream. I want to lash out to him so bad for treating me like this. But I can't, because I don't want to ruin our relationship, that's if we have a relationship at this point. I don't know anymore.....