Tried to pay online on the etihad website, all goes fine untill ten minutes later i receive a mail that my transaction was cancelled and my payment refunded for "security purposes" ???

Called HSBC and they confirmed payment went through and no refund.

Called then Etihad and talk to a representative, clearly not interested, that keep telling me i must have cancel theh transaction.
After explaining to her thats not the case she propose to proceed again over the phone.

Spend 30 min for her to understand i want the exact same ticket , and at the moment to pay she tells me my card is declined.

Called the bank again and they tell me both transaction went through...

Called Etihad and they maintain both transactions were rejected......

Not sure what to do and worst i cant even buy the ticket i want.

But really the customer service is the worst i have ever seen

First, how do you know it's EY and not HSBC which is mistaken? Why have you made up your mind as to who is at fault? "Security purposes" could mean much more than simply what your bank thinks it means.

Second, why not get EY and HSBC on a three-way / Conference call and sort this out so that neither can make a blanket statement.

Where is your billing address and where were you starting your flight from. I have had this problem numbers times on a few airlines if using my american card, but starting travel in india or Thailand (fare is in INR or Thai Baht) it a security thing. A few ways around this. One, you may not like but buy the ticket via a travel agent, even van online agent like orbitz. its still issued by Etihad and there is really no difference (unless you make changes which while allowed based in fare basis cane a pain. Or do what I do. Book the tkt on Etihad ( or whoever) and call the Abu Dhabi call center, asking them to issue the tkt. (my card has no problem charging in the UAE but if you want to play it safe, make booking, call bank and advise this charge will come thru any time, then call Etihad and have them issue tkt. I do tis for tots Ex Colombo as my cards don't work there unless actually swiped

Because i called the bank sand they emailed me document proving the transaction was accepted and money debited from my account, all processes were completed on their side.

Well it gets better,

after the very inefficient call that lasted 40 min and ended up with a girl telling me my card was rejected (again), and after buying a united flight without problem, today i receive a booking confirmation from etihad....

I have now two bookings for the same trip