Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
Try plugging the speaker's USB cable into the USB port that is on your computer itself. Sometimes USB devices will not work through an external hub connection, and must be plugged into the main device itself in order to operate properly.
(What speaker is it, and what problem exactly is it having, and did it work formerly?... I have to ask, because I have looked to see whether you have a previous question traceable, and I found no previous questions for your customer identity... not that, as an Expert, I have much power to trace your previous questions. But anyway, I have to ask, please, for those details. Thanks.)
As for your request for a refund... I cannot issue such a thing, as a JustAnswer Expert. I am limited to referring you to Customer Support at JustAnswer.com, which may be contacted through:
They will address your concern with reasonable promptness, I feel sure, if you contact them with information identifying your previous question that you wish to ask for a refund for.