Their listings say:
If you're serious about buying something why don't you take them up on it and see what they'll do?
Yes, but why not list it on their site as an option?
The only reason they wouldn't is that they would prefer users didn't choose them, and I'm curious as to why
It's going to put people off hitting the buy button or encourage them to look elsewhere as I already have, a call may seem like something minor but it was enough to put most people off leaving a mobile provider.............