credit bureau flag

I have registered with debtsafe 2017 and later that year I cancelled my contract (debtreview)with them, until today am flagged at the credit bureau because they don't want to removed the flag under debt review, every time I call them they give stories that they are not the one who flagged me ,but they are the only debt review I have registered with, they've sent 17.w form to show the withdrawal letter with them but they are not removing my name at credit bureau , now my bank cant help me with a balance transfer because of them .I have been calling and each time I was told its not them who flagged me , now am stuck and a flag to say am under debt review with debtsafe, while I have received document for the withdrawal