Student accommodation help

Hi there,
New to this so bear with me. I am a student at UCLAN located in Preston, I moved out of my family home into private student accommodation last September and have paid my rent for each term however I have got myself into a problem. I am in the process of moving out and into a studio as I need my own space and sharing a kitchen with two other people wasn’t helping me as I prefer my own space. No problems with my flatmates both lovely girls I’m just ready to be independent and live alone. I recently got a message from my landlord saying I owe him £700 to cover me from the 15th July to the 1st September which I feel rather extortionate. I’m unsure if I’m being charged extra and I am unsure how to pay this as I am not in a position financially where I can afford it and have no family or anyone who could lend me the money. Any advice would be appreciated