Who I have the same questioned this topic

Recently my cell phone was compromised/hacked. There were a few text messages sent from my phone to a number linked to a website, and then multiple unauthorized purchases were made through this particular website. I brought my phone in to a Verizon Wireless store and they did a factory reset on it, but I wanted to know if there is any way I could find out how this happened so that I might be able to prevent this from happening again in the future. Are there other cases of this happening?