Thank you for that link.
Specifically "we don't change prices based on you 'internet history'".
On any reasonable meaning of that term, that is no longer true (NB I am referring to Flexi fares only)
Generally "we try to open and upfront in everything we do" and "always open and upfront".
Discriminatory Pricing is certainly not illegal, but I suggest it is not "open and upfront".
That link did also include their Price Promise, which one could presumably use to get the relevant credit.