@Philip3095 As a community centre we cannot help I am afraid. Either the guest is continuously asking to try and get a bigger discount or you will need to call Airbnb and ask them what is going on.
In truth, as a new host, you need a large number of short stays to build a review reputation so you may be better off without a month long booking. Also, whilst unlikely, it may be scammers targeting you as a new host so just be careful.