Codelocks (KL1000 old number) KL1060 Kit Lock NetCode Locker Lock Silver Grey-New

My company bought more than a hundred of these. A few have failed and can't be brought to open using the 9 volt battery trick. Only to start working fine again after drilling them open!! Obviously, we won't get our money back if we send the defective lock back to them because they will see it working normally. That is a shame for such expensive locks.