After a while they offered to photocopy their notes and send them to you, about a week later you would receive an envelope from Sega. That's just customer service you don't see anymore.
Our forum member 'Tears of Opa Opa' has been trying to make a collection of as many of these sheets as possible. There's a few Genesis sheets and a couple envelopes in there as well.
For more information on the Sega Hotline, you can read this article:
The hint sheets listed below are all in the PDF format.