Thanks for testing, I'll look into this bug. Seems like the last lines shouldn't be in default template - maybe cot_mail() attaches these lines by default?
Well, I think I can do this (add to github + plugins), at least I'll try :)
I just have to add a check for the correct CSV structure - if the incorrect file is submitted, it might generate ugly errors. After this addition, I can say it's a complete plugin.