From what I can work out, those upgrade sprites don't relate to the turrets. For levels of upgrade you should be using an instance variable on the turret and setting it to 1,2 or 3 etc. Then you say if turret.variable=1 make it do such a thing. If you're using a menu to do this fair enough, but you cannot then reference that menu later on as though it relates to the turret.
When you select the turret you need to identify it with some ID variable as the one picked, then when the menu option is chosen, it picks the turret with that ID and sets the upgrade variable to 1,2 or 3.