overcharged since the first bill

We enrolled in the Magenta over 55 plan in February,  only because of the $70 plan and 2 free phones. Since February we have been charged 1/2 price for the phones. Each month I call and get someone that says they will look into it and call me back 24-48 hours. No one calls. I call again, and they tell me no such promotion (free phones) existed. Then they tell me if I change my plan, I could get free phones. This has happened twice, and now my bill has doubled. Has anyone successfully left this HORRIBLE  company and not pay fir the crappy 'free' phone?