T-Mobile is going on the offensive against Verizon by launching a "Never Settle" campaign that allows existing Verizon customers to try out T-Mobile's services for free.

The carrier is giving Verizon customers the ability to port their numbers to a new T-Mobile smartphone (while retaining their existing Verizon phone), which they can use free of charge for up to 14 days. After the trial, if the customers wish to stay with T-Mobile, the carrier will cover Verizon's Early Termination Fees:

After the trial, if they love the service and want to join the millions switching to the Un-carrier, T-Mobile will pay off any of Verizon's Early Termination Fees (ETFs) up to $650 or outstanding device payments when they trade in their phone and get a new one with T-Mobile's wildly popular Simple Choice plan.

If a customer doesn't want to switch over, T-Mobile will refund any fees incurred during the trial, and even cover any activation charges Verizon may impose:

If it doesn't work out, the customer just hands in their T-Mobile phone within 14 days, and the Un-carrier will refund any trial costs from using T-Mobile ... and any service costs for starting back up with Verizon, like activation or other related fees Verizon regularly charges. The Never Settle Trial starts on May 13, and Verizon customers can sign up through May 31.

T-Mobile's outspoken CEO John Legere made his feelings known about Verizon:

Last week, I said we would hit right back at Verizon — I meant it. T-Mobile's 4G LTE network is the nation's fastest. Not faster for the price … just faster, period. With T-Mobile, you don't have to settle for trickery, gimmicks and carrier BS the way you do with Verizon. I'm so confident in our kick-ass network experience that we're footing the bill so Verizon customers can give T-Mobile a try.

The carrier launched a slew of ads for the campaign, and if you're interested in checking them out, head here. Existing Verizon customers can avail the trial by heading to a T-Mobile outlet or the carrier's website between May 13 and May 31.

Source: T-Mobile