What about Hash Refinery? I don't think they have a discord. By the way, thank you to STSMiner for pointing out zpool has a discord and providing the link.
the man's alive here on BCT, and lastly about their LTC payout in this thread not long ago is:
https://bitcointalk.org/index.php?topic=676942.msg34989726#msg34989726shoot him a PM or post your address here and hope it gets seen
PM is the best contact method, but posts in this thread also get read a few times a week.
The yiimp backend should read your preferred coin from the c=xxx flag and validate against that wallet first. If that fails, or if the c=xxx wasn't read correctly it will keep trying other wallets until one says the address is valid. Many addresses are valid on multiple coins so incorrect detection is not that uncommon.
If you can send through one of the addresses you tried via PM we'll manually change it.