Keep and Switch problems

a couple of  months ago i made the switch over from Verizon. i was told i would get gift cards and to watch my email. I never saw anything. then i figured out the online site.

All three of my keep and switch rebates were denied. Well now i have Verizon wanting $1800 from me and threatening me with collections.

My issue is that a T-Mobile store employee did the paperwork and submitted everything needed. no one will help me quickly resolve the issues.

what do i do now?