Unfair and disrespectful treatment

Hi there

I have a car that I bought 4 years ago T-cross. I have been paying properly and there and there after Covid things starting shaking. But when I miss a payment I’ll make arrangements. I then realised I was not getting my statements for years. I called they said the email captures was wrong. That was fixed. Then I stated getting threatening emails and phone calls telling me I owe 20k my question was when did you realised I owe 20k and what is that for? One consultant said is for last year November. I said please go get your facts right and call me. They come back no is 7k that you missed. My question again to them when I was making arrangements for the one I was paying for why was I not told the is another outstanding? Now that I am almost done paying my car and I have paid my outstanding amount I must be harassed for something they missed? The rude consultants telling me I must learn to look at my statement? What statement when you were sending it to the wrong email?

I need them to clear my account and come with the right facts and stop calling me like I am the one at fault. I feel harassed and disrespected