Read the report how Amtel successfully helped the company to achieve this:
http://www.aberdeen.com/c/report/sector_insights/5227-SI-carriers-wireless-bills.pdf
More Carriers + More Devices = Lower Wireless Bills?
Ralph Rodriguez, Hyoun Park
In analyzing the wireless deployments of companies that use many carriers, it would be easy to assume that these companies are overwhelmed by the complexities of their operations. However, these companies actually have lower costs per user and greater savings on their wireless voice and data usage compared to the average company. In the February 2008 study Execute on Wireless Expense Management to Drive ROI, 17% of the 245 companies stated that they used four or more wireless carriers. Where do these companies manage to find greater savings when they face greater logistical challenges than their colleagues?.
http://www.aberdeen.com/c/report/sector_insights/5227-SI-carriers-wireless-bills.pdf