i'm going to take a guess here and say you did;
steel armour/iron hachet, kunlun/gold rip and iron trident yea?

can you confirm that these were what you used, or others?

cause unless you used a rank 27 or lower steel or accidently put gold fisrt then i can't explain any other way this could have happened. so can you remember exacttly what it was that you did when you press the synthesis button? and do you remember double checking that each item were in order?