First I was getting letters from Mercers and then after 2nd invoice I started getting calls from Calder. I had just sent out the 2nd letter when I received notification from Calder that Barclaycard was recalling the account with the intention of selling the debt. I have not heard from Calders since and they, like Mercers, were calling twice a day right up until they sent out the aforementioned letter.
What do I do now? Send them letter three or wait until the next lot start contacting me? Do I send letter 3 and cc to Barclays? This isn't even a major debt - its less than £500! How much effort are they going to put into collecting this!
Are you living in fear of Banks and Debt Collectors letters and phone calls? Do you worry about Bailiffs visiting your home? 

