Hey Temp,
Pressing the f3 button on your keyboard should open cords, but if that doesn't work I think it's fn and f3 at the same time.
If that still doesn't work, you can ask online staff to find your claim for you, but make sure you tell staff the last block you placed/broke there so it can be traced. (Best way to do this is to do /helpop)
I just logged off but I think madi/noctqrns is still online, so she should be able to help!