do i need to get help from the Consumer Credit Counselling Service/National Debtline or can you go to some of the firms mentioned here directly?

i have two credit cards which are at their maximum of around £19000 i have been paying the interest on these for the last number of months but i am no longer able to do this and have advised one of the companies of this and have to get back to them tomorrow what can i say to these card companies tha...