Was it worth telling him?

If you'd follow my last posts, you may know I have been having troubles with an ex- friend continuously acting buddy-buddy towards me after I ended the friendship. Today, I eventually dm'ed him asking him to leave me alone and all he responded with is 'Alright.'

Is it bad I'm annoyed at his (or rather lack of) a response? I feel as though if someone mentions you make them uncomfortable or you made them feel disrespected, you should give an apology or something more than just 'Alright'.