Send them an email and wait for their reply.
Just hope they cancel the transaction.
Last week I sent one of my tokens (ADA) to my hardware wallet which is not compatible to receive the tokens.
I thought I lost them forever as they were not in coinspot. But after a few days the transaction was cancelled by coinspot as the address was invalid.
Big lesson learnt for me. Just need to be very careful to where you try to send thm.
