I never received the 1099-Q. I just learned about it this month when i closed down the other 529 account for my daughter. No, I haven't heard from the IRS, but now that I know about the penalty and the potential taxes that should have been paid, I'm trying to take care of it before they DO try to get a hold of me about it.
Since the IRS has not already contacted you, it is unlikely that the they will contact you about this because it is 6 years ago and 529 distributions are only reported by a taxpayer on a tax return if the earnings are not used to pay college expenses. The only way that the IRS would presume that the earnings were not used for college is if they did not receive a copy of Form 1098-T from a college institution.
The 529 plan should have sent you a 1099-Q reporting the distribution, earnings, and basis amounts. If the account was worth $3,300 and the distribution was $3,000 then the basis portion of the distribution would be approximately $2,727 and the earnings would be approximately $273. Hence, you should have reported $273 as earnings on your return and Form 5329 should have been filed to report and pay the penalty tax of $27 (10% of the earnings).
If the check was made payable to your daughter, then the 1099-Q would have included her name and social security number as the recipient and the earnings would be taxable to her.