Jack In The Box

A team leader was talking to a crew member about finding another job while the gm was at the taco station, of course the gm overheard .but did not say anything . A couple hrs went by gettin close to 3 oclock the TL was scheduled to leavevat 4 to save labor the teamleader asked the gm if she could go home at 3 because labor was high . The gm told her no because she has to have a team leader scheduled 24/7 as the team leadrr turned to walk out the door the gm said to her what .you dont want to work here u dont want to be a TL anymore and before the TL could say anything the gm told her to get out and go home then about 35 mins later the gm calls the TL and tells her to come back so she does when she gets there the gm tells her to wait in the lobby . A short while after the gm comes with a write up form this TL is very good, kind always brings bags of candy for everyone in the morning .on the write up it says direct insabordination and nothing else the TL not knowing about write ups signs the paper which is then later filled out by the gm of the cause of the direct insabordination, which the TL and the employees agree never happened how would one go about bringing thisunjust GM to light. Cause I like my job but dontbwant to work for a GM like this...pllease help me with a solution