Waiting 6 months for a written off letter

My husband has an account of 5 years old that has been written off and he has been told by the lady who assisted him that she would send him an email with written off letter that was in April 2019 since then he has received no email. He then spoke to another lady who said his account has been written off but there's a percentage that has to be be paid, we don't mind paying the percentage we just need his record to be cleared. But since then still nothing we have been calling every week since then sometimes we are even left on holf for more than 30 minutes we have spoken to so many employees already I myself have about 4 different email addresses none of which exists!! He then called again last week and asked to speak to a manager but was left on hold for about 15 minutes then got cut off!!