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As @Original_Lucy mentioned you will need to contact customer service directly but just so you are aware Fido would send the amount back by cheque and by the time that gets processed your next invoice would most likely arrive. I would recommend you just leave it and it will stay as a credit on your account and be applied to your next invoice.
Hi there @darknutmeg , that's unfortunate. The only way to have your account corrected is by speaking with a customer service representative. You can contact Fido customer support by any of the methods mentioned HERE. My personal preference is to contact fidosolutions on Twitter and have someone look at my account. That way I don't have to wait on a call and the support person can work on the issue and correspond by direct message. Whichever method you choose, you will be able to get your account issue corrected. Best regards