Plusnet's handling of failed payment

[#1]

Today I returned home to find my internet was not working.
Browsing the internet resulting in this page being shown:

It took me nearly half an hour of attempting to get to plus.net before I was finally greeted with a page explaining I needed to pay a bill.
I'm not sure why the payment has failed (I have, in fact, just paid with the debit card associated with the same account that the direct debit has supposedly failed on).
Once paid, I can get to my email, one of which was sent at 12:55 today stating that my payment had failed and I needed to make alternative arrangements.
Really? So Plusnet have effectively cut off my internet the same day they informed me that the payment failed - an email I couldn't even read when I first got home!
I've never had a failed payment before, so why does Plusnet feel the need to cut me off, without even giving me a chance to rectify the problem?
That was genuinely the nail in the coffin for Plusnet - I'm finding a new ISP come renewal.

[#2]

Hi mikehiow,
I'm very sorry to hear that you had trouble accessing the Internet.
When we sent you the email (13/05/2014) this was when we were notified by your bank that the payment had failed. The screenshot that you have attached isn't a restriction due to non-payment as we don't restrict your services until payment has been overdue for more than 14 days. When payment fails normally a page will pop up advising that you need to make payment to ensure that your services aren't restricted, however, a button should also be present to allow you to continue browsing as normal.
Are you able to browse without any problems now since making the payment?