Case 2512040040001886 - Cannot Access Account

Since the 4th of December we have been patiently waiting on MS Tech support to assist on resolving our Case with no success endless calls and endless promises with no luck. How do you proceed in using Microsoft for a Business if they don't deliver on the support. My business is taking the brunt of it. I suppose another call holding for hours and another Support person promise a solution. No other methods to log complaints as you cannot log into your Account Portal.