Started well, finished with questions

I took a loan with hitachi and all was ok. I made extra payments to close this loan all the way, so on 27th of december i made a settlement payment and asked for the documents to be sent, the next day they came up with another figure to settle this loan and i paid what they asked but with one condition. i asked a written explanation of how this extra payment occurred and a detailed payment history with it. They sent the explanation email but the detailed payment history. Later i logged in to my account and i got really annoyed by this company as it was showing a balance as well as next monthly payment with a due by date so my loan was still active yet they sent me an email saying loan was settled, if i leave this balance, it will only incur extra interest on top of it every day, in my experience i felt that this company took more money then they should, i called them many times but waiting time was 30min to 1 hour (sometimes i had to give up waiting as i work also) , so it is not easy to reach them even by using internal messaging system on their website, it is a big problem if you cant reach to someone. this is such a company which they can cause problems to anyone who would like to finish their loans earlier. I am still waiting for an answer as i told them they have to send me the payment history to show me where that extra payment i made fits in even after the last settlement payment. It is certain that i will never get a loan from this company.