Bad service

I just discovered that money was not taken from my account 2 years ago when i was trying to apply for a house. No one has contacted me to tell me that I am owing. What is worse now is I am calling all the Wonga numbers available to arrange payment i have been taken from pillar to post. I am told my account is closed, i will be called back but no one called till today. My credit score is very much affected and what angers me is the fact that i want to fix that but no luck of getting anyone that will assist me.