Visa Reward Card

I moved in July 2023, and had my internet set up.  At that time, an "AT&T representative" came to the house to introduce himself and try to get me to switch my cell service over.  This guy told me that my total bill for internet and cell plan for 3 would be approximately $60 cheaper than what I was currently paying. He told me that I would not have a cell phone bill until my old provider was paid off and on top of that he offered me three $200 reward cards to help make my final payment to my old cell provider.  Fast forward a few weeks later and I get my first bill saying I owe them $734 or would be sent to collections.  What?  How?  I call to inquire and apparently this "AT&T representative" sold me a bunch of (Edited per community guidelines) and was later terminated. I assume for doing this to others.  So my too good too be true deal from AT&T was exactly that, and I now owed $734 over what my normal old provider would have been.  WHY THE (Edited per community guidelines) WOULD I SWITCH PROVIDERS IF IT WAS GOING TO COST ME AN ADDITIONAL $700 OUT OF POCKET???  Then my regular bill was actually MORE than what I had paid before.  In order to accommodate me their solution was to drop my internet to a cheaper plan and take off the insurance for the phones.  I'm a newly single mother on a budget.

Fast forward to the reward cards.  Two of them didn't work.  I again called to ask about it and after approximately 3 hours I was told new cards would be sent.  This was right before the holidays.  I was busy and forgot about the cards, and it was only recently that I remembered that I never received the replacements.  I just called them now for them to say, "Sorry, they expired and you forfeit the money."

So I signed up in July.  I paid an additional $700+, received cards that didn't work, and now I'm told they expired and I have forfeited the $400 balance!  The rewards center then transferred me to AT&T to speak to about it.  AT&T said I have to speak to reward center.  I said they literally transferred me to you, I didn't call you.  The representative says she will call the rewards center and transfer me to someone that knows what they are talking about.  Evidently no one knows what they are talking about because she hung up on me!  What kind of operation is this?  

Any suggestions?