Nobody wants to help

My account with you is in arrears. You sent a tracer out to my workplace to fill in debit order forms which I did 2 months ago , to date no debits have come off the account but Im getting calls and demand letters still? How do I trace back who I signed that forms with and How can your call centre staff not check this in the collections department? I am calling in constantly to enquire about this and not getting help? Do you want the accounts settled or not , I cant understand the lack of response and ignorance from some of the staff. Please Help.