Non-Responsive Travelstart

I need to push out my flight to Europe by 1 day to attend my father-in-law's funeral and I've had absolutely no response from Travelstart using the online form they direct you to, since Sunday, despite numerous attempts (even using the urgent flag as my flight time approaches). Today is Thursday - I'm due to fly tonight and all I need to do is move it to tomorrow. But still nothing. Book DIRECTLY with the airline people, where managing a booking and making such changes is so easy in comparison!