Hello Gavmoulds,
From what I have learnt, this is a very common tactic from companies where debts have been included in a bankruptcy. As stated above, they have no legal powers to retrieve any money or possessions from you. They will as you are finding out, attempt to retrieve what they can.
Have you checked your credit file recently? If not sign up to noddle, its free, and even though it may not be considered the best source of credit information, it will at least give you another perspective on what is happening. It will also show up if any debts that were included in your bankruptcy are stiil "live", and Noddle will offer free advice how to get this changed. You can of course use experian of equifax.
In the short term, try not to worry about any companies that contact you regarding payment for debts that were included in your bankruptcy. Longer term, you need to be thinking about getting your credit file updated correctly, should this not be the case.
Search on here for harassment letter templates, edit the letter and add details of your bankruptcy. Your case number, date and court should be sufficient to start with, and send away. If you keep getting them, reporting them to various bodies will also help.
also request a copy of their complaints procedure.
good Luck