[Lola and me]

Hi today I went out and bought a new hammy (my old one Pickles a boy died yesterday ) My new one is a teddy bear hamster I named her Lola. Anyways cleaned out the cage and everything else my old hammy used put new bedding food and water. She went into the cage and I left her alone for a couple of hours. Later looked inside and saw her eating so I let her finish and I put my hand in to try and pet her and she started to run away. I understood that she wasn't used to me so left her alone with a tissue that had my sent ( I read that that helps for them getting used to your scent) for at least four hours. Later my mom went in and tried to pet her and she squeaked I learned that it usually means that they are scared so we left her alone for 2 hours. Then I went back in and tried to pet her. She jumped on her wheel and started to run. I think that makes her feel as if she's running away. My question is how do I get her to let me pet her the store that I bought her from said that I couldn't return her so I don't know what to do plz help!