Unable to Call from Puerto Rico

[HPSPIKE]

When in Puerto Rico the first week of September, neither of our two Fascinates nor our other plain Samsung  model would work.  We got several bars of signal strength.  We could get to pressing the send button and then they would go back to the previous screen.  At the Verizon store today, they could not tell us why this happened.  We were in Puerto Rico earlier this year and the phones all worked flawlessly.  However, with Verizon, all we could get was 1G since Verizon does not have any of their own towers there.  They sold them to Claro a few years back.  Now it is all on extended network.

Anyone have the same problem of ideas?