Please hold first.
They rolled back their database by one day due to some error and as a result ALL invites that I sent within the past 24 hours have been wiped.
I have spoken to the founder and he told me to give him 24 hours as he wants to make sure it does not happen again.
Once he has reissued the invites to me, I will send them all out again. Apologies for the mess up. Out of my control however :(.