You did nothing wrong, but the answerer didn't want to make those changes
Hi, I'm the mod who deleted those comments (and others) in response to NLN flags from the post owner. We generally take those as "I've decided not to implement these suggestions" (in the case of no edits) and delete the comments (suggestions which will not be acted upon are obsolete).
In some cases we might post a comment saying suggestions have been rejected and removed, and encouraging users to use their votes, post an opposing/better answer, and/or just moving on, but that's also an effort and noise consideration. We generally expect users to understand that comments are temporary and to move on in response to rejected suggestions, and so would usually only post it in response to repeats. But don't worry, everyone has to be taught this at some point, and we teach/remind of this fairly frequently.