Maybe Terminated for Theft That I Didn't Do

Hello,I am the lead stocker at a grocery store in Virginia,i have been there since August last year.I was promoted to lead in a month and half,then I was going to be the grocery manager in a month from now,I am a hard worker,great leader,but anyhow at the beginning of the month I was working and was on lunch.I went thru a line and the guy ringing me up said he had a discount card,he rung my 2 bags of mini chips and hotpockets,$3.19 total,uses his card and starts bagging my stuff,I reach for my wallet,open it to give hime money,I look up he puts the receipt in my bag.I then look at the screen and everything is zero's,receipt also.I asked him was he sweethearting me,a term for not scanning items but making it look like it.He then has the card and said no it was legitimate.I walked back to the back room and something just didn't seem right and told my grocery manager,I told him that I would pay for the items,also inform my store manager.He said not to do either because he was going to speak with store manager the next day when she was in.It also happened to him and one of my stockers,several occasions.Fast foward,I go in today,loss prevention has two of my stockers in separate offices.First thought was damn,I'm gonna have to work hard tonite,I've had many employees get busted for shoplifting,didn't think much of it,I don't steal so I'm not worried.I start working and the assistant manager comes and tells me to follow him,lo and behold,they want to talk to me,wth,they tell me what it's about,I explained and wrote what you read above andhe told me that they are going to investigate it,he asked if I knew about the card and I told him I was unaware of this ,they have these discount cards unbenounced to me,that cashier's have to discount customers to zero items on a $50 or more purchase,kinda a customer appreciation thing,not for the employees use.He told me 10-15 other employees were being investigated,he even told me he saw the footage showed me try to give the cashier money,but unfortunately we don't have sound on any security footage,it's basically like watching a Charlie Chaplin film, they could not hear me question him,some people got fired on the spot.This only happened once to me,I also reported it when it happened,almost immediately, what I heard people,alot of people continually did it,I was told to go home,had to give up my store keys.My store manager said she would call me,I guess to tell me if I have a job tomorrow.
Should I quit,try legal help,idk what to do,i didn't do anything wrong.

Please help

Maybe Terminated for Theft That I Didn't Do