Default MAC address hacked... need help

I'm by no means an experienced android rooter/hacker/developer... whatever... so please, be kind.

I have reset my note 10.1 2014 edition numerous times and still, someone has access to my tablet. After reading a bunch of crap on the web, it appears that my MAC address has been compromised... Short of selling this thing and letting someone else deal with the problem (no, i'm not actually going to do that) what can be done for this issue? Can I change the MAC address? Is there a program to firewall all my info? It doesn't seem malicious at this point, just seems like someone wanting to screw with me/people. But I can't do anything besides light browsing on the web or reading a book without fear of my data getting compromised... I even have freaking tape over the cameras... UGHH! help if you can. Thanks for taking the time to read all this.