Difficulty with booking an air ticket

I booked a ticket with JetStar. Their website is slow and buggy, so it was quite a hassle to make a booking. They offer many complicated and unnecessary choices - which are meant to give additional marketing revenue, but increased the difficulty of using the website.

After going through the hassle of selecting the itinery and the seats, I had to make payment. I painfully entered the details of my credit card (as MAS refused to allow the airline to store the credit card details) and confirmed the payment. I had next to wait to receive a verification code sent to the mobile phone. When it arrived (after some delay), I entered the verification code. There was a long wait and finally the website went blank. I clicked on another webpage and found that the payment was not processed - as the verification code had expired.

I went through the pain of making another booking. This time, it was rejected as it was a "duplicate booking". I am unable to recall the previous booking, so I deleted the original booking and make a new booking.
My third booking was  rejected as a "duplicate booking". So, I am now caught in limbo and don't know what to do. I searched for the hotline of Jetstar and could not find it.

I draw this conclusion - the website designers try to put in too many options, which made the process complicated. MAS comes in to impose requirements in the name of security, but no one looks at the whole process and think about simplifying the process for the consumer.