I dont wanna go to a meeting, what excuses should i say to not offend a friend?

I was invited to attend a meeting about World Financial Group lastnight by a friend so i agreed instantly (because she's a friend) without thinking anything, lol. I searched in the internet this morning about the company that said it's an MLM. I feel like it's just a waste of time and MLM is not my line. I'd rather spend my weekend volunteering in the thrift store coz i'm having fun there. And besides i read comment from people wasted their $100 paying that background check and asking relatives and friends contact info. Heck, i won't give up my relatives and friends info. Now, what do i say to a friend to cancel that appointment? Should i tell the negative sides that i read in internet about the company or should i make other excuses?