I found this:
If you have paid a third or more of the total amount payable, the goods become "protected goods" and the creditor must go to court for an order for the goods to be returned unless you consent to the repossession. They cannot just come round and remove them ("snatch them back").
WARNING: If you want to work out if you have paid a third or more remember to include any deposit or part exchange as well as the instalments that you have paid.
If a creditor "snatches back" goods without a court order and without your consent where a third or more has been paid, you are entitled to a refund of all the money you have paid under the agreement.