Very Weird Question

My PC is heavily hacked. That is NOT my problem, unless it's doing stuff to my hardwired phone.
I'm in no trouble from the hacker; my data is safe elsewhere, and I've been studying it.
But what just happened might be done by the hackers, and THAT really IS a problem.

It could be something wrong with my phone connection. But not the phone itself, since the same thing happened when I switched from one phone to another.

I do not use ANY wireless devices. I use W7.

I tried to call a local number. The first 3 digits are 766. After the first 6, I got a recorded message that the number I just dialed "doesn't exist". That's simply impossible. "76" is not a number. I hadn't even really dialed a whole number. Receiving calls, no problem.

My question is this: Is this possibly caused by a hack? If so, can someone explain to me how it could have been done? I'm blocked from calling ANY local number, even in the 765 area. I don't even know how the phone company could do this. And yes, I'm paid up to date. My hack is an extremely sophisticated one. all over my PC.