I am not too sure, but I have read somewhere that encouraging someone to use credit to pay credit is classed as an
unfair practice.
Simply do this. Draw up a statement of your incommings and outgoings. From your outgoing, remove necessaries - food, bills, rent, taxes, etc.
Whatever is left should be your debts. Now work these out pro-rata and offer a payment of whatever is available from your remaining money.
So long as it is reasonable (e.g, you are not spending £80 on your mobile phone each week) then a court would accept it. As such, the creditor should accept it also. Request that they freeze
interest and remove charges.
This is explained in more (and better) detail in the debt forums.