I have poor signal strength on all our verizon phones in Ponca, Nebraska. I asked the local verizon store for help and they said it is like that in our area and it is best to complain to Verizon directly...
The coverage map shows there is coverage not the quality of the coverage. To complain about the signal, you should call Customer Service at 1-800-922-0204 from a landline or non VZW phone. If you can get through you can try *611 from your phone.
You might want to check www.sensorly.com to see what the crowd sourcing community has mapped for your area. There is also Root Metrics with a similar crowd sourcing map.