Norman Bisset Call Back rating of 0

I was contacted about 2 months agon by Norman Bisset, and made arrangements to pay outstanding balance over 2 months, this was completed end of August, now they are wantinf to Debit my account again. I have tried to conatct the office no on the sms i receaived, *** which has a standard waititng time of about 15 to 20 minutes, then as soon as someone answers, the call get cut... Or as soon as you ask the consultants name they say you through to a debt collection company instead of their names, then the call is cut. I need someone to contact me before the next unauthorised debit order will be deducted, coz i can only imagine what a mission it will be to recover my money....