If possible, you should also ask your landlord to sign a check-out inventory report, when you hand over your keys. Hopefully, they’ll give you your full deposit but if they try to withhold some, make sure it’s for valid reasons.
They legally can’t penalise you for wear and tear and if they say that they have to pay for a room to be redecorated, make sure they’re not charging you more than it would cost.
Your deposit should have been placed in a tenancy scheme, and if there is a dispute, you can contact your scheme's alternative dispute resolution (ADR) service. They deal with complaints and should be able to resolve any issues fairly.