Think Ive Made A Huge Error ( Kribs )

[corrina67]

after a lot of research i decided to get 2 kribs for my tank m+f they seemed to be fine yesterday, checked in my tank this morning and my 3 corys have gone in to hiding 1 has half a tail and a couple of other fish are missing chunks out thier tails, im sure its the make krib and im not sure what to do, will he settle in a couple of days or should i just take him back i really dont want to lose my corys thier like my little babys

 

[black angel]

Kribs like to have the bottom of the tank to themselves and once breeding, the cories will get punished even more. I would take them back to the shop.