It is very strange that they will deduct money from your account before you have signed anything. I would suggest that you arrange a meeting with them to rectify the problem. If you have signed their forms it means you are officially under debt review.
Debt review is a voluntary process and you are allowed to exit any time you want. There are a few risks involved however. If you exit before your debt has been repaid, all your accounts will revert back to the original contractual terms. this means that you will have to pay the original instalment, at the original interest rate and the original term.
If you are sure that you are able to afford this, you simply need give written notice to your debt counsellor of your intention to withdraw and they will initiate the proceedings.