My iPhone 4s won't make calls or receive text

Hello I have an iPhone 4s With the latest iOS 8.1.2 and I can't make any calls with it. First of I have all signal bars and I try to make a call a few seconds pass and I get a call failed message , when I try to send a text message i get a message saying failed to send text message.

I personally called my Phone carrier they said they didn't find any issues with the signal and asked me to change the sim card just in case is the sim card ,after that I changed the sim card and still with full bar I get the same messages.

I personally tried these solutions that I found here If you can't make or receive calls on your iPhone - Apple Support

None of the solutions there worked for me and I have reseted the Iphone 4s 3 times and no luck.

So anyone has the same problem or if you had fixed it let me know I been with this problem for 2 weeks when I updated the Iphone 4s to iOS 8.1.2 so I don't know if it was the update.

Thanks.