Recently unable to consistenly sendreceive phone calls or text messages iPhone

You have defined this issue to be occuring in 2 defined locations.  @ work and @ home.

This is typically signs of the carrier having problems with provisioning your line properly, or your phone having issues being allowed on their network.

I would try ultimately trying to Restore the device as brand new and see how the phone behaves without restoring any back up information.  It is possible your back up has corrupt/invalid data affecting the service also.

My recommendation :  Have provisioning checked on your account, if everything checks out, restore your device to factory settings and DO NOT restore from a back up.  See how the phone behaves, if the issues continues, you are still looking at a provisioning issue.

Here is an article to help with restore process for a refresher.

http://support.apple.com/kb/HT1414

Thanks for the suggestion.  I'm a little nervous about losing my contacts, etc...apps and music aren't a big deal. 

Would you mind explaining further what "provisioning" is?  I'm admittedly not very tech savvy (which my teenager finds very irritating), but I've managed to muddle through thus far. 

If I restore and it still doesn't work as it should, how to I sync from a previous backup?  Does it give the option for which backup to sync from?

Oh, I also visited my carrier's store again (a different one this time while I was out and about today).  They once again insist it's the phone and suggested I take it to a different Apple store from the one I went to previously.  They claim the store I went to is new and that the Geniuses may not know what they're doing.  The associate I spoke to stated he lives close to where I am and that he has never had network issues.  Since hubby and daughter can get service, they feel it's likely the phone with the problem. 

Provisioning is like programming for the phone on a carrier network.  Meaning, if something isn't set right, then your phone could have issues talking on the network.

I would also think to consider other services on the phone also.  Is 3G data working in the locations you are at but its text messaging and calls that are having problems?  Those are usually signs of provisioning problems, not the phone, because 3G data services run fine.  If 3G data services are also having problems, restore the device a brand new and see how the phone behaves without any personal data on the phone.

It is usually a good idea at this point to see if Applecare Technical Support can further assist you, though if you out of support, they may charge to get clarification on the issue.  It's always difficult to place blame back and forth on an issue like this because there are SO MANY factors that come into play here.