I'm a little confused, so, may I have a bit more information? The iPad does not come with a phone icon, like the iPhone - mainly because it's not a phone. So, it doesn't have the hardware or software (stock) to make calls. To make calls on the iPad, you have to installed a 3d party app such as Talkatone, Whistle, Skype, etc. to make phone calls.
Which app are you using to receive phone calls? If we have that, then maybe we can figure out why that app won't let you "dial out."
Thanks.
Marilyn