False account

I am being harassed by cartrack agents. In June 2025 I canceled my contract with cartrack and there was a settlement amount I had to pay. I struggled to pay the amount all at once and eventually in October I paid the settlement amount and emailed the proof of payment to their account department, sent it on watsapp and even called to ensure they recieving it. Same month, a few days later they debited my account for the same car and I reversed the amount. Now I am recieving nonstop calls, emails and watsapp massages stating that my account is in arrears. Everytime i make the agent that is calling aware of this info the say they will call back and never does. Same as their emails, I respond with this info and they never get back to me except when the demanding the payment. I have asked numerous times to be transferred to their senior account supervisor but they always come with the same answer " she is not available ". I'm tired of explaining myself and not getting any help.