You can cancel a plan at any time with no extra charges or fees. As soon as you cancel, you won't be charged any more Instalment Plan fees but the remaining balance will then become subject to your standard purchase rate, which is higher than your instalment plan fee.
If you decide to cancel, any previous monthly fees that you've already paid won't be refunded.
You can easily cancel Instalment Plans in the credit card section of the mobile app.
Once cancelled you will not be able to set up a plan for this transaction (s) again.