Closed loan from 2014 showing arrears

So i app**** for the getbucks monthly credit report so that i can keep an eye on things. I noticed a loan from 2014 still showing up as arrears. So i phoned in and the lady said that she will contact accounts to get this sorted out and i should give it a few days to update, this was last week. So i phoned in again today as i saw nothing had changed. This time i was told that the manager will be emailed to get this removed and i should give it 21 days to update on all the credit services. Now tonight i receive an email saying that i am in arrears and must pay this amount which is now active again and that a debit order as been loaded and i cannot make a new loan until this one is settled. How can a loan that i paid up become active again a year later and now is so far in arrears its not even funny. Whats the point of phoning in to get help just to get more headaches? Please help as i frequently use your services and always pay. I mean you cant even take out a new loan without the previous one paid up?