Change of principle member

I have been trying to change the principle member on my medical since the 28th of September. All docs have been submitted but i have been getting the run around grom the call center. Had the issue 'escalated' 5 or 6 times already but still no progress. Every time I call in I am told that they will call me back in a few hours and confirm the change. Nothing has happened. Worst experience I have ever had with Momentum.