Why does my a/c keep turning on after I shut it off complet. then turns on itsel

I did add 1 of the small cans

With what you describe , adding freon , without proper gauges/equipment , can make things worse. May be an electrical/control issue , or the field coil/clutch may be weak. HINT----- Have someone else turn the A/C on and off while you (with a bright light for best visibility), watch the clutch to determine how well it is engaging-- Do you hear a good 'click' when turned on , or does it appear to slip or is it a little 'jumpy' then leave it on and see if it gets 'jumpy' after a few seconds or minutes (whatever time it normally takes to 'fail').

Yes it works but I have to repeatedly push auto so itt will kick on but when it does it blows awesome