Instant Upgrade payment declined
I have made repeated efforts (trying different UK credit cards) to buy an "Instant Upgrade" for my upcoming flight from LHR to YVR - but in all cases the payment is declined. My card issuers say that this is due to the website's failure to implement the correct 3D Secure protocols and there is nothing they will do to allow me to complete payment. Since the Instant Upgrade from plusgrade is only available online I cannot get any help with the transaction from the call centre. Can anyone suggest a solution - or am I doomed to travel in economy?