Lost credits due to import/export issues and lack of undo button - frustrating experience

I just lost half my damn credits because of stupid import and export tweaking my columns and random cells running which causes me to lose all of my information. Also there is no command z or undo easy undo button which makes everything difficult as a noob. I understand the power of clay but its frustrating when I lose $200 worth of credits for unfriendly UI even when I'm being careful. I just want more credits man.