DEBIT ORDER NOT CANCELLED

I have a personal loan with old mutual which I have been paying for and had a debit order for it. I advised them in October 2015 that I am no longer employed but self-employed and requested to cancel this debit order. i made payment arrangements and honoured them. Recently I called to make a second payment arrangement and that I can write a motivational letter to reduce my instalment as I depend on my business to make an income. I did that and submitted my forms to the branch. I received a call from a consultant demanding payment and not aware of anything that I have done . Each time a different consultant calls who has no clue what is going on and I have to explain myself all the time. I was requested to send a bank statement for october which I did but the email address given is incorrect. I keep receiving sms of failed debit orders on my account since October yet I have requested to cancel. Old mutual helped me with the loan and I am willing to pay but can I be assisted accordingly please.