At Spreedly we rarely do any phone pre-sales or support, and that's a very intentional choice. As noted above, good phone support is expensive to provide, and one of the ways we've decided to keep costs down (at least for now) is by sticking to email. For those who want phone pre-sales and support, Chargify's offering looks like it could be a good option.
Totally understand the reasons not to offer this, but we feel it is pretty important the ability to call your billing provider 24/7 and talk to someone as well as a NOC that is staffed 24/7 monitoring all systems. Collecting money is what makes a business work, sending an email that someone might get to the next day just is not good enough for us.