Poor service

i have apply for a phone with this company and their delivery company called me to delivery my phone they said to me they only allowed to delivery the phone at work or police station i told them that I am currently on leave so we can meet up at police station they refused i said to them they can just cancelled everything because I am on leave for 3 weeks, they cancelled the order, but now they deduct money into my account and they make it monthly deduction when i went to the bank the canceled the debit order but they told me that they might deduct again so i must contact them which i did and they told me that they have cancelled a debit order they are lying i didn't take their phone it went back to them why they still has an active debit order into my account?? please help me because they don't want to cancel this debit order.