Yes, anything. I only use as a last resort, after sending a few letters like it souds you have already done. I get the dept upto around £40 i.e two cleans and a latepayment charges covering extra house visit costs to collect money. The buy the dept, but only give you around 25-35% of the value. But having added a few charges on I get close to the original bill. At least I get something back for it without spending to much time or going to to much trouble. Plus the customer does not get away with messing you around. Makes them think twice about doing it to the next WC they pick on.