Unresolved Z Axis Jammed

Hello everybody. I got my Robo 3D Plus and i did all the software configuration an step by step video to set the printer. I noticed something was wrong with my home command because it ended up with the Z axis going allways up and everytime went higher and higher. When i tried to print a calibration circle it did all the starting procedure and ended up printing in the air. When i searched online i saw that the problem was the Z axis switch but when i tried to fix it i found out that my Z axis is jammed on the left side. I dont know if i have to unscrew the nut on the bottom and try to release it so before making any mistake that i can regret later i will ask you guys.
Probably they hitted it on the plane but i am a little bit scared since i went through so much trouble to get this machine in my house. I will upload a video and some photos to clear up the problem.