Power of attorney letter required?

Keep in mind that I am deaf. Last year at this month I sent the email to RCS Group to ask to increase my credit limit (for Dionwired) where I was told that I have to call myself to the customer service to process the manual limit increase. There I left it at there because it was not possible. then last week I resend the email to the person called Zulpha Charles because of the direct email address (easier communication than to the call center/customer service). There Zulpha informed the custom service to help me with no answer until today, I resend today again where the customer service informed me that I have to get the power of attorney letter to process the manual credit limit. I found this redicilious because if I was not deaf, do the normal also require also the attorney letter to process the credit limit? I have RCS account for longer than a year. Always on date paid. I have many proofs here that I am deaf and that I can send to tell that I am the customer myself who needs their help. No answer so far. I will not recommend this RCS of Dionwired credit facility/service to anyone.