Phone return not credited

[Susanamy]

I traded in 3 phones. I have ups receipts that shows them delivered. After 6 conversations with Verizon—all claiming to have corrected the transaction, I am still not getting the credit. I will switch my carrier if it is not fixed within 3 days!  How can this be done!  I have 4 phones and 2 iPads on this account.  You would think Verizon would want to keep my account.