When they ask those questions they are not looking for the answer "no" or "yes because..." Rather, if your response is "yes I was fired" they are looking for what you learned from it and how you are trying to overcome it. As you acknowledge, it is is never good to lie. You have to explain the situation for example was it an isolated incident or not. Then how you are working on making sure that doesn't happen again.
Obviously I dont know what happened, but an appropriate answer would be, "Yes, unfortunately I was fired for talking on my cellphone while at work. It was an isolated incident, however I realize that I should have been focusing on my job rather than being on the phone even that one time. To avoid future problems I now leave my phone turned off throughout the day."
(This type of answer can be applied to explaining explaining employment gaps too.)
Even with an answer like that you get someone that doesn't care, you just have to move on. I used to teach under/unemployed individuals (many were recovering addicts, previously incarcerated, or had no stable home) how to get a job and be prepared for working. Sometimes no matter how good of an answer you can give, people don't care. Don't let that get you down. You have to move on and apply elsewhere.