Default Relock bootloader without using recovery?

Hi.

I am about to RMA my phone and need to lock the bootloader..

BUT - I cant get into recovery.

I have tried everything, reverted to stock image (followed the thread how to return to stock image) , but no matter what, I cant boot into recovery.

I can get into the bootloader / fastboot , ie and run adb commands, but I cant boot into recovery.. its just flashed the google logo and then gets tuck there ..

Is there any way I can relock the bootloader given my predicament?

it's doing some other pretty weird stuff.. pretty sure the battery is near flat, but If I plug it in to charge, it flashes the charging logo and then about 10 seconds tries to boot,.. flashes the google logo and then about 1 second ofthe spinning colour circles.. then just black screen.. even if I go into the bootloader and hit power off..

If anyone has any Ideas I would love to know.

Does anyone know if google will RMA with an unlocked bootloader or am i screwed? This sucks!