W40K: Assembling Tyranid Termagants

Well, as I mentioned earlier today I was going to change my Tyranid list to match the model quantity in the box.  So I started assembling my Termagants this afternoon.  I assembled the first box of 12 without any problems.  I then opened the second box and started to cut the pieces away from the sprue and I noticed claws on the sprue.  I said to myself why are there claws here.  I doubled checked the box and it said Termagants.  I check the other 2 sprues in the box and they were correct Termagant sprues.  So it looks like I received 1 sprue of Hormagaunts in my box of Termagants.  Without that 1 sprue, I can only build 20 Termagants.  So it looks like I'm back to 2 units of 10 Termagants.  Hopefully when I buy my Hormagaunts I'll get all the correct sprues and then I'll be able to run 2 units of 14 Hormagaunts.