Air Transat Flight only booking. Offering a credit only instead of full cash refund.

rosiesposies

 The consumer law applies in the country the company is registered to and what website they purchase from, not where the consumer is based

I’ve booked plenty flights with air canada on their Canadian sites, Canadian consumer law applies not U.K. if I booked with the U.K. website or call centre, U.K. consumer law applies

selling to, and buying from, are 2 separate things. 

Credit cards offer additional protection, but consumer contract law in the U.K. doesn’t apply to all global websites unless they are marketing specifically to the U.K. market. 

DPS-2016 said:

Surely UK rules apply to sales in the UK?  
For example, a supplier in, for example, South America, must comply with UK product standards if they want to sell to a UK customer via their website.  Otherwise it'd render product standards useless - domestic suppliers would always be undercut.  
If this isn't the case, it ought to be.  
Either way, in my book, pay for a service in good faith and get refused a refund equals a valid chargeback claim.  And then boycotting the airline.  Legal in Canada or otherwise, it's morally reprehensible.