Horrible experience booking airtickets with Travelstart

My husband was trying to book flights for our family's December holidays on Travelstart website on Saturday night, and he made some mistakes which I picked up within an hour, and tried everything possible to cancel the booking on Travelstart even before payments was processed by them:

1. Called their Afterhour emergency line on Saturday evening and Sunday morning, and couldn't get through at all. Despite the voice prompt on the emergency line said they should be operating DAILY until Midnight ! I even left message on the phone and NOBODY called me back.

2. No ways to cancel a PENDING booking on the website. Website is operating 24/7, you should have call centre support 24/7 covering your full operating hours if you do not allow clients to amend and cancel their bookings ONLINE. I should be able to at least cancel my booking before payments were processed!

3. I send three emails to ********** throughout the weekend. NOBODY came back to me before Monday afternoon 13:59! Service turnaround time is appalling !

4. When I phoned in to travelstart and spoke to the consultants, she promised me that she will speak to her manager and get the back to me within 15 mins. She never did until I phoned her back 2 hours later and she said her manager was in meetings and can only get back to me the next morning.

5. I booked Flexi tickets, and I requested them to change the flights to my correct days, they told me one flight was fully booked when I checked on Singapore airline's website where the flights are available at the exact same cost. How can they tell me that the flights are full? Do they think their customers are that stupid that they don't know how to check the seats availability on other sites to cross validate?

I have used Travelstart quite a few times in the past, and after this awful experience, I will never ever use them again, and will tell that to everyone that I know.

Flight booking is very time sensitive, if you cannot provide the abilities for your customers to do everything themselves online including changes to their booking, then shut down your website when you do not have Call Center staff working! As simple as that!