How long is too long?

I took my boat in for an overheating problem on Aug.3,2009,they said it would probably be the weekend when done.I don't hear back from them so I call on Aug.9,2009 and they tell me they got swamped and didn't get to it yet.I was out of town so it was no big deal,I tell them I'll be back Aug.15,2009.I just called and asked what was wrong with my boat and they told me the IAC needs replaced it would be in early next week.They still don't know what the overheating is.They have had the boat for almost 2 weeks and still don't know what's wrong with it.Is this normal for tow boats?I had a Y pipe replaced on my old I/O and that took less than a week.