Billed for returned defective phones

Correct Answer!

Our I Phone 12's were not working so Verizon replaced them. We sent the 2 phones back as instructed in a timely manner. Have receipt from UPS with Tracking Numbers that shipped to Verizon on 12/23/21 and delivered on 12/29/21. Just received text from Verizon devices never received and they are charging us over $900. I've called customer service number times and waited on hold multiple times for for 60 minutes each time. Also did the online customer service and got as far as receiving a message that that they help and then would receive a text something happened and got disconnected. Tried calling store and same thing, on hold forever and nobody picks up..

I need this addressed immediately so I don't get charged for phones that I returned. Please help!