Course materials are only refundable during the first week of classes. This time frame may be shorter or non-existent for some B-term or shorter-length classes. Once the final return date has taken place, all course materials are considered to be final sale and not refundable.
Some physical copies cannot be refunded if they are opened or the access code opened/revealed. Textbooks being returned must be in the same condition they were purchased (i.e. new books need to be in pristine condition with no signs of wear).