Where or how can I file a complaint about a supervisor with AT&T's customer service

I seriously have never been spoken to so rudely by someone in customer service - or anyone for that matter - in my entire life.  My husband and I just signed up with AT&T on 2/1/21 and the agreed upon charge was for $152.  However, as of today, 2/2/21, there is an additional $88 charge on our bank account from AT&T and we were not made aware of this charge in any way, shape or form.  There is nothing on our order form from yesterday in that amount.  I had contacted customer services a little while ago and the first gentleman I spoke to had asked for my bank card number in order to investigate our AT&T account.  I thought that was an odd request and so I told him that I'm not comfortable doing that.  Plus I would think he could see the card info from the order my husband had placed with them just the day before.  Then he started asking if I was present when my husband had placed the order with them and was I sure he didn't have something else charged to on our debit card.  they were very odd questions.  But he could not see anything but the $152 charge. But he didn't sound too sure of himself so I had asked for a supervisor.  This man got on the phone, didn't ask my account number, phone number, and told me that if I'm refusing to give them the info that he needs (our debit card number ) in order for them to properly investigate our account and then he basically blamed our bank for this extra charge on our account.  He was so rude and ignorant.  He cut me off the entire time - I actually screamed at him at one point and then almost immediately after I screamed at him, I hung up the phone.  The only name I got for him was Joe and I really cant believe he is a supervisor in your customer service department.  We just signed up with AT&T yesterday - we don't even have our phones yet and we're considering canceling the service if this is what's to be expected when we contact them for support...