I would like to get refund for a character transfer.

I want to go back to horde, is it possible?

did you try?

What message do you get if you try to change that character to Horde?

I tried, it says that transfer is only available from Horde -> Ally.

ok, then I guess you have to wait they active the standard "change faction" feature but it will cost coins ( and/or points). It will not be free.

Since you asked a "refund" remeber this part: " Faction change is irreversible and not eligible for refund " when you accepted the "free" faction change