Great, thanks. Does anyone know if there is a template for a Subject Access Request on here anywhere?

Hi everyone I have just received a letter, forward on from a previous address (I moved over a year ago) from Call Serve Ltd, referencing Debt Managers Ltd - NPoower Ltd, for a debt of £500. I have, over the past couple of years, been receiving letters for this debt from a variety of debt collectors, although I have never been with NPower in my life. With some DCAs, I have written to them asking to provide proof of where this debt is from, and they have advised me that they have passed the debt back to their client as they cannot give me the information I asked for. Is there any way I can make these letters go away for good? After reading other threads here, I am going to send them the letter requesting a copy of the CCA, but as other people have commented, as this is for a utility bill, would there be a CCA to send me? Any help/advice would be greatly appreciated! Many thanks Anna.