T-mobile Fail to honor company discount Nationwide

T-mobile offered me a 15% company discount to switch to their carrier.  So I switched to T-mobile and purchased two new t-mobile ready phones.  However, once I started receiving bills and inquired about why my discount was not applied, I learned that T-mobile was refusing to honor the 15% discount they promised me – they claimed my company’s discount program expired one year prior.  I have been in a dispute with t-mobile for more than 3 weeks but just keep getting passed from one representative to the next.  It appears they have no intention of honoring the 15% discount.