Moving into the rented

Moving into the rented property went smoothly but moving out didn't. Terrible communication from Belvoir Colchester, 5 weeks after moving out had to chase for my deposit as I had no contact from them. Then less than 50% of my deposit appeared in my bank account followed by a breakdown of charges. I was charged for a full house clean without my knowledge, even though we cleaned thoroughly before we left. Three and a half months later, Belvoir Colchester are ignoring my emails and are withholding overpaid rent which they owe me. Don't touch them with a barge poll.