Please pay my money back that you owe me

I have never received a Statement on my account. My account was already paid up and I had to ask them for a Statement. They sent me a paid up letter but they owe me money. After many emails and proof of my payments I am still waiting for them to refund me. Very quick to phone you if you skip a month but very slow when they owe you. I hope I will get my money from them soon. Customer care is not helping at all.