Open Question: I have a…?

Razr phone and... the piece of crap doesn't want to work, the screen won't light up and usually I can get it to come back on but today I think its done. I have an old cell phone I could use until March 20 when the contract is up but no charger. My mom wants to buy a converter piece to stick on the end of our car charger since it would only cost 5 bucks but Id only be able to charge it in the car and it'd always be dead which would defeat the purpose of having it. What can I say to my mom to get her to get an actual charger? Im 18 and my family and I lead hectic lives so its kind of mandatory to have a cell phone. Because my mom has to drive me everywhere, i cant get a job because she wont drive me to one and because I live where its effing cold in the winter im not walking to a job.