Samsung 850 EVO can't erase, unmount, boot, or anything else

Hi all, I have a really bad problem that seems not to have a fix. i was running OS X 10.10.3 when I decided to check out the beta for OS X 10.11. Well the second beta patch installed, not the actua operating system. Now my disk is fooled into thinking it's running OS X 10.11 and it's impossible to do anything. Is there any way to fix this? I am currently booting off a recovery disk and I got error 69888 when attempting to force erase the disk through terminal. I'm desperate at this point because I just spent almost 200 in the new disk and now it's become unusable! Thanks for any help

Tim