Vodafone gigacube charged twice

[VJtomer]

I have ordered Vodafone Gigacube on 5th September 2017 and started on 8th Sept 2017. My account was debited (29.98 + 43.38 = 73.36 Euros) on 21st September.
But, in the current bill on 20th Oct also, my account has been debited for 73.82 Euros. Please let me know that why my account has been debited twice and refund the unnecessary debited money as soon as possible.

[Andre]

Hey VJtomer,

due to an error in our billing system a small number of customers were charged double.
All of these false transactions have already been refunded.

Please check the statement of your debitaccount.

If you did not get any adjustments, feel free to send me a private message.
Therefore click on my name -> then on the right side "Diesem Benutzer eine private Nachricht senden".
I need your customernumber & password.
Then I'll have an closer look.

I am sorry for the inconvinience caused by this.

Best regards,
Andre ^and