If Paypal could not get the funds from your bank account then it Paypal may have ended the subscription.
Don't worry all you simply need to do is Login to your Client account and click the 'My History' tab -> click on the view invoice image (of the unpaid invoice) and it will give an option to pay the invoice there and then by clicking on the paypal logo under payment method.
If you have already paid an invoice the 'click here to pay' text will be replaced with 'the invoice has been paid'