GO2bank complaint: SENT MY DOCUMENTS THEY SAID TO SEND AGAIN, SENT AGAIN CERTIFIED MAIL AND THEY NEVER PICKED IT UP

So I filed a dispute bc I ordered a phone from Boost Mobile and it never shipped til after I cancelled it on the 6th day. I sent them all my documents right after I initiated the dispute. But 3weeks and they said they didn’t receive it. So, I sent it again this time certified because I wanted to make sure they get it. When it got to the post office I called support and sent a email sending screenshot of the tracking history and the notification it was there for them. I can never speak to anybody in the disputes department I always get a rep who says ‘i will note it in the notes for them to see. 2 days later I get an email saying they never received it and to send it again! I’m livid! What the hell! On top of everything I reached out to boost Mobile regarding the issue and they stated that the chargeback request was accepted and successfully sent back. SO WHAT IS THE ISSUE! I have no money do just to send certified I had to borrow the money. But I’m grateful I did so I can say it’s there! The support person had the nerve to ask me what is the PO box I sent it too and after I read back the address has the nerve to tell me, well ma’am I don’t see it in your file can you please mail it again to that PO BOX. I HATE CALLING THEM OR GOING THRU THE HELP SECTION IN THE APP BECAUSE THEY GIVE NO HELP!!!!!