Executive Resolutions rep. doesn't answer any of my calls or emails

Executive Resolutions rep. called me and left VM, I called her back after 15 mins, and left VM, but she didn't call me back. I called her number more 20 times, left multiple vm and sent multiple emails, but she completely ignoring all of this and my case is still open with no solution.  I called and asked to talk to a manager of her, and as promised more than once a manager will call me, which never happened. HOW CAN I GET THIS ESCALATED? WHO CAN I SPEAK TO & HOW?