Thanks for the advice dx, I'll send off a CCA request ASAP. I'll keep you posted on the outcome

I have recently come into contact with a debt collection company called Global Debt Recovery Ltd, based in New Malden , Surrey. I was sold a loan approximately eight years ago when I was young and naive from a company called Welcome Finance. The original loan was approximately £1000. I don’t have any paperwork from back then so I can’t be sure of the exact amount. I eventually ended up in financial difficulties and was unable to make the repayments. Years passed and various reduced payment plans failed and after while I had no communication from them and I was unable to make any payments. Recently I received a letter from Global stating I owed a total of £7, 800. Due to being extremely busy with work and family and with shock and disbelief of receiving such an awful letter, it was filed and forgotten. No excuse I know. I also began to receive telephone calls at my place of work, mainly when I was not there, I work shifts and the calls were made during office hours. My colleagues and managers passed on that someone was repeatedly calling and asking for me, they would not say who they were and were extremely rude and persistent when informed that I was not there. I apologised and said I would sort it out. The same person called every day, now he gave his name and said he was from Global and it was urgent that I call him immediately. One of my colleagues had to hang up on this person as he would not accept that I was not at work and was avoiding his calls. Unfortunately my place of work does not record incoming calls. This has caused me great embarrassment as you can imagine. I have written a letter to Global stating that this is harassment and that I wish to be contacted only by mail. What would anyone advise if they do not comply with this request to communicate only in writing and continue to contact me at work? I have informed them that I am aware of my rights and that I will take further action if required. I’m just not sure what that action will be yet! Once this is resolved, I guess I should begin the process of finding out how exactly I owe the amount of money they say I owe them!! Sorry for the long post and thanks in advance for any assistance.