Clearance letter

I had enter in to debt review in 2017 then paid all that I needed to pay, my mother adviced me to stop because when I finished I might have a big sum DAT I still need to pay so I stopped. Then started paying allvmy account on my own,the pioneer group called me and told them I want to cancel everything then I had to pay a cancellation fee paid it and the lady told me wen I'm done I must go to them for my certificate. Last year November paid the last two that where left when I went to the pioneer group office had already collected the paid up letter,they told me that one of the paid up letter reference number doesn't match there's,when I call the company they told me that that's the reference they know and pioneer group did ever help me in any way even today I'm stuck I don't know what to do please help.....thank u