Xfinity identity verification problem for device purchase

On 10/12/23, I purchased two phones off of the xfinity website. An iPhone 15 and iPhone 15 pro max.  I went through the  identify verification for the iPhone 15 and it has shipped.  I went through the sane process for the pro max and xfinity stated they could not verify my identity!  In addition , the cancelled my order and cancelled my $850 rebate and said I could try and purchase again with only a $370 rebate.  UNACCEPTABLE!  Does anyone have a number or email to corporate?  I asked for a supervisor when on the phone with the rep and he told me ALL of them were in a “meeting.”  I pay far too much to xfinity for this.