horrible reception with iPhone 6s and 6

Seriously considering returning to our iPhone 4s and iPhone 5. We NEVER had problems talking on theses phones from our house. Now, with our new 6 phones we have to walk outside to talk!! And, when my husband is at his office, he has to walk outside to talk. This is unacceptable. Our phones are crucial to our work! What is going on? We have called tech support and was told "it must be our carrier." Not true. We NEVER had this problem before. Getting NO HELP from Apple!!!!! Not that it matters writing on this forum other than helping our mental health. I am sure they are not read by Apple. Very frustrated and unhappy with Apple.