I recently purchased a iPhone SE on prepay plan in August 2016. Is there any way that I can cancel this current monthly plan and go back to the normal buying $20 top-ups when needed and only pay off the phone instead?
You'll need to speak with the Vodafone retention team in order to switch back to prepay. If you are paying the phone off you will be charged the phone in full once that change has been made. You cannot have a phone repayment scheme on PrePaid
The retention team is open Mon - Thurs 8am-8p and Fri 8am-6pm