If you are still looking for help with your answer, I would be glad to be of assistance.
Parenting has its ups and downs and it certainly sounds that you are in one of those tough places with your daughter. At 14 years old there are lots of things changing within her and outside her. School work, sports, and friendships can all put tremendous pressure on a youngster. Still...a 3 week period of this attitude is likely putting you over the edge.
I would strongly encourage you to get the following parenting book:
Parenting with Love and Logic by Foster Cline and Jim Fay
It is the best parenting program out there...easy to read, easy to use. Simple - straightforward.
If you go to their website - there are many helpful tips.
Since your daughter has changed friends, has been disruptive in school...and then the sports issue - there is definately something going on here. And...this is the time to open up communication rather than shutting it down.
I know your first instinct is to punish her by taking away cell and computer assess and to push for am explanation of what happened at school. However..that did not work...and instead you get more hostility and anger. So...would you be willing to change tactics here?
My experience tells me that what she needs is compassion and understanding not punishment. She already is in pain - hurting for some reason that you don't know about.
Because sports is an avenue to good self-esteem...I would encourage you to help her with the try outs. Call the coach - explain the situation - ask that he/she please consider allowing her to try out. Taking away this part of her identity and this source of self-worth is only going to prolong the pain and misery that she is feeling. She needs to hear that you are on her side...that you have her back. Sure ... she made a mistake in the lunch room..but that "sin" does not equal the consequences of not playing on the team. Believe me...I have been in this same situation many times and the cost of not helping her will leave you regretting this action.
So...again...call the coach. Show your daughter that you truly love and care for her. Then...you will have an opportunity to say...okay I helped you with the try out...now help me understand what is happening that has you angry, upset, and in such a bad way.
See...by your taking the high road here and helping her...you are opening the door so that she can tell you what is the matter.
I hope you find this helpful. Certainly I am offering you a different approach...and from years and years of experience working with kids and parents, I know that this can be successful for you.