Boundaries are really incredibly important, and those who refuse to acknowledge them are showing precisely what they think of you. Get rid of them. You don't need that shit in your life.
A healthy relationship is about mutual respect, and if something is bothering you, and you mention it, and the person doing it refuses to stop, then that person doesn't respect you. They don't love you. Love also requires respect.
Normally, the pattern is a promise to change, and then absolutely no effort. That way confrontation is avoided, and they don't actually need to do anything.
Sometimes, though, there is a flat out refusal. In that case, people might tell you your boundaries are stupid, or you're stupid/wrong/broken for needing that particular boundary, or for feeling violated, angry and or frustrated when that boundary is crossed.
You are not.
You are not wrong.
You are not stupid.
You are not broken.
They are utter arseholes.
Incidentally to act of getting you (or trying to) to doubt the validity of your own thoughts and feelings (known as gaslighting) is something that abusers do. It's textbook. If someone you are in any kind of relationship starts doing the above, get out. Get out. Get out.
And I mean any kind of relationship. Abuse, emotional or otherwise, isn't just something that occurs between lovers. Parents, siblings, friends, coworkers and employees are all capable of becoming abusers.
The constant crossing of boundaries is a giant red flag.
Boundaries are incredibly important. They're vital for mental health. If someone is crossing them, deliberately or otherwise, speak up and stand firm. You are worthy of that respect.
Get rid of anyone who tries to tell you otherwise.
And for the love of all things good and green, if someone tells you that you've crossed a boundary, pay attention, and make an effort not to do it again.
Otherwise, you're an arsehole.
This has been a public service announcement.