Incorrect Billing and fight for deposit

Roxanne Mott and Debbie Mott claimed that my previous owner had to pay them my deposit in order for them to pay me my deposit and advised that it would take 7 days, it took more than 20 days and they were not responding to emails ,had to call multiple times before I got hold of them. I decided to contact the previous owner and only then they decided to pay, but they deducted electricity for a month that I wasn't staying at the flat for. I sent emails regarding this matter, I am still waiting for response till today and it's been more than 5 days.