Unfair business practice

Requested a settlement amount for a loan I took with Finchoice, I was emailed the settlement quote, I settled my loan. After 3 days when I checked my account there was still a balance on the account, I called to inquire I was told it's an error on their site and it will be rectified, after weeks of calling and sending emails iam told there was a system error and I still have a balance owing.