Rebate Promotion Not Honored

I ported in two new lines in March because of the promotion stating that if a line is ported in and you BYOD you would be eligible for a $450 rebate.  Both of my rebates came back as invalid.  When I spoke with customer service they said that my two new lines were not eligible for the rebates because my phone numbers originally started with Verizon (12ish years ago).  I've been with another carrier for about 5 years now.  How is that not considered 2 new lines?  

The customer service rep stated that there was nothing that could be done to help since my 2 new lines were not "new" lines.  

I then asked if I could be assisted with backdating canceling my lines since I'm not eligible for the promotion that convinced me to switch back.  They would not assist me with that either as I am now outside of the worry free guarantee policy.  But it took this long to get the rebate rejection.  I'm stuck with prorations from the old service carrier and $200+ in prorations with Verizon.  I paid off my devices with the old service carrier in order to port in.  I was able to do all of this because I was under the impression that I would receive $900 to apply to my bill.  I am not in a financially sound situation right now and made the decision to port in because this promotion would have saved me money.  If there was any wording at all in the promotion stating that my lines would not qualify, then I never would have made the jump.  

I am extremely disappointed in the lack of assistance and understanding.  I feel completely mislead by the promotion and feel that it should be honored.  I read the small print on the promotion (again) after speaking to an agent, and nowhere does it state that my lines would not be eligible.  I requested a supervisor and the agent told me that they would tell me the same thing and would not be able to help.  

Does anyone have any advice?  What should my next steps be?