Health Club = bad at math?

I talked to a trainer recently who told me, "no matter what gym you pick, they're going to try to rip you off".
(side note:  by "gym" she meant gymnasium)

I'm not sure that I know this to be entirely true.

Here's what I do know. 

I went to a local gymnasium and went with their two week free special.  I used the club every day for two weeks and figured I had a little momentum, so I'd sign up for their "no contract $19/month" memberhip.

I actually took out the little coupon and showed the sales-fella.

He said, "ok, but that's the alternate day plan"

me:  huh?

him:  You could go Monday-Wednesday-Friday or Tuesday-Thursday-Saturday.

me:  I kind of wanted to go Monday through Sunday...ish.

him:  Oh, well that's $30 a month with a $39 setup fee.

me:  Well I figured that the sign that said $19/month meant the whole month.

him:  nope

me:  and this coupon said that there was no initiation fee.

him:  there's not - just a setup fee.

me:  what's the difference?

him:  this is to set up the membership

me:  oh...of course...I'm an idiot

And scene

A year later I was shopping health clubs and took a look around to see if I could find a better deal.  I'd already negotiated my other club down to $20/month...but figured I could do better.

I went to a new place (I don't want to name it - but it's very urban...and active) and signed up for two years at $10/month.  I figured I have a little traction and don't fear the contract any more.  I paid up front and now don't have to worry about monthly fees.

Or so I thought.  They've charged me twice...so far.
And the guy I work out with told me they just charged him again.

Now I understand that kinesiology and math are very different...but seriously?