UPS lost my phone, verizon charging me over $300

Mailed my iPhone trade in iPhone 11s in August. Was told $700 per phone promotion. UPS tracking shows no movement and I lost the promotion due to phones not being received. Verizon keeps “fixing” and then losing the credit and now I’m told it’s my problem to make sure the phones get there but UPs won’t help bc it’s a Verizon provided box/label! 

I’m at a loss. Verizon says it’s my issue and ups says it’s Verizon’s issue. About to pull my business and take Verizon and or UPs to small claims court -$1400 for the lost phones and now paying an extra $120 per month! 

anyone have any success?