Discover Bank / Discover Financial Services review: Credit card

My adult son had a medical issue last september and is incapacitated. I went to court and got legal guardianship of person and of estate. All boxes checked. I have been trying to deal with his bill at Discover and they will not talk to me, they say my paperwork won't allow them to talk to me and they want to talk to my son to get authorization. he is incapacited! I have the power to talk to all of his debtors. Every debtor has responded with kindness and sincerity and is working with me, some writing off his debts. This isn't a huge bill. Around $1100. The last guy I talked to wouldn't even give me the email address of anyone to send info to. I called today and got forwarded to two people, the last one never came back on the phone. The last guy I talked to got ticked off because I tried to tell him that I have no other paperwork. The paperwork I have is from the probate office, signed by a judge. He wants me to go back and get more paperwork? He said I needed to call whoever issued those papers and get better ones! There are no better ones. The letter I got today said they would write it off as a bad debt, but would still pursue payment. AND I could call the number and they would perhaps deal with a smaller amount as a payoff. No they won't. They won't talk to me. They know how many times I have emailed and asked for help. The guy on the phone told me that. But would he give me a better email address or repeat the address I previously had? Nope, nada, nothing. I am a 64 year old mother, trying to help my son during his incapacitation and not getting anywhere.