You can remove the link from footer.php file. See at the left hand side and go to:
Appearance==>Editor==>Footer.php
First of all, make a backup by copy all CSS codes on Footer.php file on a plain notepad. If you have done so, press CNTRL+F button and at the top of your right hand side, you will see a box. Type in “https://themezee.com/” or “BizzCard Theme by ThemeZee”. Once you found it, you can delete it forever from your blog.
Anyway, it is advisable to get a permission from theme developer. I don’t think they will allow such action.