promo code not working

It is such a bad experience dealing with customer service at Xfinity. It has been 3 months after numerous phone calls, tickets raised without any resolution to my issue.  In the month of March I received 2 promocodes regarding 50% off new Iphone 15 upgrade and one I used successfully for my daughter's phone but I couldn't use another one because of the system glitch, since then I visited store, made numerous phone calls, every time I call they create new ticket and bounce me from one call to another and ask me to wait some time 7 days, 14 days, 48 hours. After that I get one standard message from the reward department that they are unable to fulfill at this time without any explanation whatsoever. This has been going on from March 12th. Today one agent said I have been calling wrong department number I should call [Edited: "Incorrect number"], when I called it went to some tracking card department. I am really sick and tiered of this. I absolutely hate to deal with Xfinity customer service departments.  I really don't know what to do. Is there a right number for Xfinity rewards ? I don't want to deal with BOT.