MRL 788, welcome to Team Estrogen! I can't add to the great advice already given but just wanted to welcome you and make an observation.

Congratulations on recognizing that bike was not right for you and having the gumption to return it. The lure of just getting out and riding is strong, but shopping for a bike can be a lot of fun too if you approach it that way and not let confusion frustrate you. At first you will be confused because sales people will give you confliciting information and high pressure. Stay away from those kind of people and shops. When you find a shop that will be helpful to you in the future you can recognize that quality by the type of questions they will be asking you and how much they are trying to understand you and your riding desires. That distinguishes a shop that is trying to get you to fit into what they are trying to sell you.

Someone mentioned trying various shops because they can only sell certain brands. That is really key to this. All the major brands carry the kind of bike you want, but not all will be suitable for you and trying them out is the only way to find out. It takes time, but keep it fun and the time will fly!