Why does T-Mobiles customer services suck so badly?

Getting a refund out of these scammers is nearly impossible. We've spent over 9 hours total on calls with them over the course of a month, every so called "account manager" promises to resolve the issue and every time the issue does not get resolved. The promised callbacks are ignored and the service continues to decline. Best is to dispute it with your CC company or pass it on to an attorney, which is what we're in the process of doing. They can deal with the Scam-Mobile.