Ok, but did you discuss it with her as far as what you wanted? And she agreed to make a video of what you discussed? For how many minutes and wearing what costume, etc? If you two didn't have a conversation and she is a new model or there is a language barrier, maybe she didn't know/understand what "custom" actually means.
Sorry this happened, maybe it is best to send her a polite message to clarify your expectations. And if you didn't have an agreement before paying it's one of those live and learn things, I guess.