I will add this bit about having depression. Depression isn't always as simple as not being able to get out of bed in the morning. Someone can be mildly depressed and be pushed over the edge by something simple (like having a phone taken away). So stop and think, are you feeling extremely sad or has losing your phone made you mute? If it's the latter, you may what to get a diagnosis from a doctor instead of a forum. ^_^;
Now...As for the phone...analyize the event that caused you to lose it.
Why were you asking for a SIM card in the first place?
Did you simply get mad and leave or did you get mad, shout something, and then leave?
What do you mean by no-service-cell phone? If that means it doesn't work then why have it? Who are you call?
There is a chance that what you consider "persuading" you mother saw as "begging/whining" and what you see as "walking away mad" she saw as "temper tantrum". In short, you could have lost your phone simply as the result of miscommunication. With the answers to those questions you may be able to dicuss getting your phone back and getting the SIM card in a calm manner.
Instead of persuading, start a discussion about the SIM card. Why do you need it? How would having the SIM card help you with school/friends/culbs/ect.? If it's done calmly, you won't get upset if your mom says no anyway. Whether you get a yes or no about the SIM card, you should at least get your phone back in its original form.
Betta Buddies: Jet <:))))<(\ (\
( ^_^) This is Bunny. Copy and Paste Bunny into
(_(")(") your signature to help him gain world domination!