Strange Billing Error

[#1]

Hi, my bill is due today (14th), but first...I didn't receive an email informing me that my payment would be taken in 3 days.
Second...I just checked my Mastercard account and there is a very strange Plusnet Cancellation item paid into my account for £22.73...the exact amount of my monthly bill.
My bill every month is due on the 14th, there has been no charge for this months bill due today.
In my Plusnet account under view my bill, it doesn't show this months bill as paid, but under my usage it has reset as it should.
See attached pic of the money paid into my account at 7.35 this morning....it seems like there's been a glitch in the payment system at Plusnet towers...or have I been given a gift.

[#2]

Is it a refund of a payment taken in error that you are aware of?

[#3]

It could be, but not that I'm aware of, I just got off the phone with someone at Billing and they've checked and texted me just now saying everything is fully paid and looks fine on Plusnet's side.
Just need this month's bill to be taken sometime today...my bill is usually taken between 8am - 9am every 14th.

[#4]

Hi Glenn,
That is very odd - can't see any reason for it, and it's still showing as fully paid on our systems. I'll mention it to the billing team though.
As for your latest invoice, that's now showing as fully paid so it's gone through as far as our systems are concerned. Hope that reassures you.

[#5]

The money that was mistakenly paid into my card account was taken back out last Friday the 17th...although no one told me it would be taken out...it was fortunate I had left money on my card.