How do I change what I use to pay my pay in 4?

[HRodg3rs]

I started a pay in 4 a few weeks ago and my paypal is attached to a card that was stolen then cancelled a week ago. Whenever I try paying my Pay in 4 an error occurs (obviously). I can't remove that card because its tied to the pay in 4 so I added my NAB bank to paypal to buy things. Whenever I try paying my pay in 4, Paypal will not let me use my bank to pay and won't allow me to use my card (as its been cancelled). 
I can't used my cancelled card to pay the scheduled payment and Paypal refuses to let me use my bank to pay... 

[PayPal_Nick]

Hi @HRodg3rs,

I'm sorry you're having trouble adding your bank to your Pay in 4 plan. To use a bank for this, you'd need a valid card on file as a backup source of payment. If you want to make future payments with a new card, you can change your payment method by logging into your PayPal account, going to Pay in 4 and selecting the Pay in 4 plan you want to change. There, you can click “Change” under “Payment Method” to update your information or choose a new way to pay. If you are adding a new debit or credit card, you'll need to confirm it before you can use it for repayments.