Sorry but this is very poor advice.
Cyanide you are scaremongering and not helping!
OP do this.
Step 1. Goto CAB, see what they say.
They will help you and can contact the debt collection agency on your behalf to pay in installments. ****Only what you can afford**** Do not worry.
alernatively
Step 2. Goto Consumer Action group Forums
http://www.consumeractiongroup.co.uk/forum/
start a thread on there asking for help and expressing your concerns.
Someone will help you.
Are you 100% sure it is a bailiff/officer of the court who is sending you letters? I very much doubt it is......
Because if it is just a debt collection agency then they have zero powers to inflict CCJS or whatever else they may be threatening!!
Secondly no they cannot take anything from your house. You are in no way obliged to open the door to them. In fact DO NOT open the door to them. if they contact you by phone and try to get you to pay in full whilst threatening you with all manner of unpleasantness DO NOT PAY - hang up!
Just tell them to send you a letter - dont deal with them on the phone.
Finally do not worry - debt collection agencies spam these letters out all the time. Thats not to say you should ignore it because its CT debt so you need to deal with it.