How to convince my parents to get me a phone?

All my friend has it but not me. I got an iPhone 3GS when it came out. And now I feel that phone is out dated. So I stopped using it for a year. And I wanted an iPhone 5 badly. If I could go to work, I would. But sadly I am just 13. I always ask my mom if I can change my phone. She said " You have to get good grades. " I disagree, cause I hate to be studying just for that. School is nothing if you don't have specific knowledge. Then I asked the other night, she said " I have no money. " She sometimes use that, she always lie about having no money. I kept on lying to my friends, cause I have no choice. Now I am trying to earn as much money as possible to buy one. I hate saving money. I asked my dad but nowadays he always supports my mom. So no point of asking him. So what do I do to convince him, I cannot lie anymore to my friends. I am running out of reasons. Help me, please. I would grateful who ever has the best answer. If your answer is about, be grateful of what you have, please don't answer. Cause I really hate that sentence.