Can someone else, like a parent or Citizens Advice, deal with my landlord or agent for me?Beta*

Yes. Write to the landlord or agent giving the person's name and saying they can speak for you about your tenancy. Because of data protection rules, the agent may refuse to discuss your details with anyone until you have done this. Once you have, there is no good reason for them to refuse to deal with your representative. Keep a copy of the authority you sent.

Sources: Citizens Advice: getting help from an adviser