Dropping calls

[My3doxies]

I have been having issues dropping calls.  I live in a semi-rural area with the interstate only being about 6 miles down the road.  My phone never has more than 3 bars at most times and sometimes only 2.  I drop on average 2 or more calls per day, it's beginning to be quite annoying because people are thinking that I'm hanging up on them.  I did upgrade my phone to IOS7 and it didn't change anything.  I am not eligible for my full upgrade until March and I'm not really wanting to use my warranty because they'll only give me a refurbished phone. 

Does anyone have any insight?

[Ann154]

In a good to excellent signal service area, dial *228, option 1 to reprogram the phone to the Verizon Wireless network and to update your PRL (roaming list).