University of Bedfordshire-accommodation,booking deposit

Hi
I’m starting uni this September & will be at the Luton campus in Bedfordshire. Currently I’m trying to fill out these requirements on student village .It says I have to pay a deposit off 200 pounds ,which is fine but after I’ve paid that it will take me to a section that says pay first rent . I’m just wondering why I have to pay my first rent so soon ? I haven’t been in this section yet as it requires me to pay for my deposit first which I haven’t yet done but each section is labelled with subheadings before you click on them in this occasion it’s “pay first rent” . Ps I have tried calling Bedfordshire but they never answer , or I’m on hold for minim 10 minutes then it hangs up & ive also emailed them but they have yet to respond to me .