INSURANCE POLICY NOT CANCELLED

I met with a broker, who gave me a competitive car insurance quote. i signed the initial quote. I was then sent a follow up "final policy document" to sign which had the incorrect residential address on and a very different higher premium. I advised that I will not be signing it as it was not was initially quoted and that my details were captured incorrectly. It was then amended but still came higher than initially quoted. i then went back to my current insurer and asked them to re-quote. They came back with a reduced premium. I then advised Discovery that I will be cancelling my policy with them with immediate effect as I received a lower quote from my current insurer. A little over a week later I received an email from the broker assistant that she had mistakenly not cancelled my policy as per request but that she was doing everything to cancel it and that my account may still be debited as a result. I was advised to let them know when it happens so a reversal could be arranged. I then contacted them when two separate debit orders went off my account. The broker advised me to reverse the debit order with my bank to speed up getting my money refunded. I then did this. I informed her that I reversed the order and requested proof of cancellation. She then sent me back communication from the CEO that I have defaulted on my policy but not honoring my debit order. I find this ridiculous as this will reflect badly on my credit record as "defaulting" when it is Discovery Insure who did not do the necessary cancellations. I have written to them to have this altered and requested proof of cancellation but have received no response since then. I would appreciate someone from Discovery amending this as soon as possible and that no further debits will go off from my account and that my record will be cleared.