Maybe it wasn't quite adjusted right Diva. Was the waistband sitting on your hips, not your waist?
I find i need the arm straps loose-ish so i take most of the weight on my hips. The strap that joins the two shoulder straps together needs to be at the right height too.
Don't give up yet! Play with the straps a bit and see if you can get it sitting better.
I find it as comfortable as my HAB...... hope you do too soon!