Thanks
Mr MCO for the BAA tip. However, similar to what
Roger points out, the online acknowledgement of booking indicates that only 50% of the one-way fare will be charged to your card (GBP6.75 in the case of HEX) but the email acknowledgement states that the full fare will be charged. Interesting!!! I have sent an email to point this out and will post the outcome when I receive an answer.