Thanks for the advice will repost when I next here from them

I am new here which is my regret, I have spent a few hours reading through numerous threads and have found some fantastic advice, but like I say really wish I would have looked on here sooner. I am being chased by Lowell for a debt on a credit card, for however long I assume they chased me at my old address, i was totally unaware until they contacted me at my current address, unaware of being able to ask for a CA i rang them today after i had a card through the door and asked for an expenditure form to be sent to me at which numerous points the dca refused saying "call centre only". My first question is by me asking for the form is that a way of acknowledging the debt ? unfortunately i do not think the debt is more than 6 years old, i believe it to be around 4 years old. My next question is there a governing body people can complain to about dca's and the way they handle themselves when calling people ? My last question is what should i do next ? Should i still send in my £1 request letter and see what the outcome is ? Also what happens next if they do send me through the request ? Please can anyone help would be more than overly grateful.