Independent of AA, the Synapse Co. is a "crooked" outfit. But sometimes you can come out ahead: I've subscribed to magazines through Synapse, most have lowball 1st year rates < $10/year. Eventually they DO mail you a high priced renewal notice (and if you read the very fine print), you DO have the option of cancelling by calling their 800 number--sometimes they will let you renew at rates as low as $2/yr., otherwise just cancel.
If you go to http://www.synapsegroupinc.com/, you can cancel magazines from Synapse.