No accountability

I am a Onedebt client and have never missed a payment with them ever, however since November 2017 I have been getting a call from VW Finance telling me that my account is arrears which I was not aware of, so I called my portfolio manager Natasha and she told me she will liaise with VW Finance and get back to me, sadly no one at Onedebt gets back to you as promised, anyway long story short, till today I am still getting calls from VW Finance and Lewis Stores now harassing me and threatening me with legal action. I was under the impression the reason I am with onedebt was to avoid all of this but to my surprise seems like I have caused more harm than good. I am still waiting for someone to call me as everytime I call its the same story, we will get back to you, its been 3 months, I am tired and need advise or help if possible to move another company maybe.