T-Mobile's doing even more to try prying wireless customers away from Verizon and AT&T. At this morning's Uncarrier 9.0 event, John Legere announced the "Un-contract," a commitment on T-Mobile's side that guarantees customer bills will go down, but never increase unexpectedly. "I'm bringing back the contract," Legere said on stage. But unlike the long-term agreements that T-Mobile phased out long ago, Legere described this one as a reverse contract — from T-Mobile to you. It also locks in all previous Uncarrier movements and data packages as permanent. "I'm guaranteeing those rates for as long as you're a customer," Legere said on stage. The Un-contract goes into effect starting March 22nd, and T-Mobile says it will also protect unlimited data plans from higher pricing. Further, Legere announced "Carrier Freedom," a new program that expands on the company's previous "we'll pay your ETF" offer to cover up to $650 in any payments you currently owe Verizon and AT&T. That's per line, and T-Mobile says it will extend Carrier Freedom to cover up to 10 lines. With this change, T-Mobile is going after people who may feel tied to upgrade plans on AT&T's Next and Verizon Edge. You'll still need to trade in your current smartphone and buy a new handset from T-Mobile if you want to qualify, though. Previous T-Mobile Uncarrier announcements have included Music Freedom, which allows customers to stream popular music services without it counting against their data plan, and a Jump early upgrade program that led T-Mobile's rivals to roll out their own alternatives. More recently, Legere unveiled Data Stash — or rollover data — which tacks any unused data from a customer's billing cycle onto future months. T-Mobile has also discarded long-term service contracts, added complimentary overseas data coverage, and allowed potential customers to test out its network for a week.