software bug

I have an iphone XR, 4 months old. I'm having major problems with text messaging. I've called Apple support 4 times & they seemed to be giving me standard answers that didn't fix the problem. I finally demanded to speak to a Supervisor/ trouble shooter. We've been working to fix this problem for 2 days an hour first time & over 2 hours last call. Finally it was identified as a software problem. They are aware of the problem with other users but have not developed an update to fix it & say I have to wait for a new IOS to be developed. I requested a new phone & was denied,instead they stated eventually there would be a fix for the bug.

The problem is in the middle of an Imessage it will freeze & response box arrow turns green. A message comes up to report junk & says contact unknown. The contact is in my contact list & happens after we have been texting for awhile. It use to happen randomly every few days but now everyday all the time with others using imessage. How can I get Apple to give me a new phone?