Jet people are refusing for my account to be closed

I settled my jet account in order to close it but I was told to come after after two days for closure as the new balance doesn't reflect immediately and I did just that but to my surprise when I got there to close the account I found new balance that I don't know anything about and because of that new balance I am unable to close the account, we have been trying to call their offices for three days now with no progress . I regret the day i opened this account