Harassment complain

Hi I would like to lodge a complain about the staff from Lewis store in Dundee....I bought a TV from a friend not knowing that he is still paying for that TV.....now it's been 2years since I have that TV and 2 weeks back they came to my house to take that TV and they said they were sent by this friend of mine.......I told them that I have that TV bt they must contact the account holder to come and settle the payments not me....yesterday they came and threatened me that they will not leave until they have the TV....threatening me and my kids. I don't have the account with Lewis......and I never purchased anything with them. I have names for the staff bt it seems as the other two guys were not from Lewis because they are not known and don't work for Lewis.