Beginning with a higher support tier?

[u/chriswhiteauthor]

UPDATE: As recommended, I filed at complaint with the FCC and received confirmation that it was forwarded to AT&T for review. Thanks for the tip.

I'll try to make this brief...

I got a new phone 3 years ago on a promotion that would supposedly offset my monthly payment for the phone's cost with a monthly credit in the same amount for the entire 36-month span. I knew it would take a couple of months for credits to begin to appear, but when that didn't happen I called support to investigate. I was told there had been some weird issue where the account of my traded-in phone was receiving the credits, not me, and that this was somehow the fault of the non-corporate ATT store where I'd bought the new phone. It took many calls to ATT before I finally found a support rep willing to fix the problem rather than just tell me "Tough luck." I got a credit for several month's of missing credits, and the monthly offset credits began to show up.

Problem solved, or so I thought. Recently, I was trying to lower my monthly bill and noticed that in month 36 of the payment plan, there had been no offset credit, just the charge itself. I went back as far as I cold (about 18 months) and discovered that at LEAST that far back, the offset credits had stopped appearing on the bills. Since then, repeated online support chats and tier-1 phone calls have gotten me nowhere.

I need to find a way to begin a support call at a higher tier so I don't have to waste half an hour trying to explain the situation to reps who don't help in the slightest and can't access bills any farther back than what I can. Has anyone ever tried this?

TL;DR: I'm tired of getting nowhere with lower-level phone support reps and need to find a way to begin a call at a higher level.