Trade in issue

My trade in is still pending despite shipping my old phone a few days after starting my service with Xfinity Mobile.  Tracking number shows it arrived at its destination a few days later.  A few weeks later my account shows the trade in is still pending.  I call customer service and they tell me they have confirmed the phone arrived at the warehouse and validated the condition was accurate according to my claim.  They said my credit would start on the next billing cycle.  This was a lie as it did not start.

A few weeks later I call and same deal, they verify the phone was received at the proper condition and the trade in would be applied.. another lie

A few weeks later same deal.  This time they apply a one time credit and tell me everything is good to go.  Another lie. Same deal for another few calls.

A few weeks later same deal. More lies.  I ask the rep to provide evidence when he says that the trade in credits were going to be applied.  He said he couldn’t but promised everything was fine.  It’s been about a week and though my statement hasn’t arrived the trade in is still pending on my account.  

I don’t understand the purpose of the lying .  Can you resolve this issue without lying to me?

@user_520kkh