The US Y to UA E change at MP posting is still happening

. Every government Y US codeshare flight I've flown since February has had this problem. Every time I've called MP C/S and spent 20 to 30 minutes on the phone bickering with an agent. Each time it escallates to a supervisor and ultimately I get the Y basis EQM posted.
The last supe I spoke with suggested I contact 1kVoice about the issue.
Thoughts on my next steps? Contact 1kVoice? Write a letter? Keep playing the MP C/S game?