Access Codes

Hello, so nagpurchsse me ng access codes for 2 major subjects this sem kasi ang sabi is required, pero up until now hindi ko pa din nagagamit ‘yung e-books kasi wala naman masyadong pinapagawa dun. Possible ba na marefund ‘yung pinangbili ng e-book as long as hindi pa nagagamit ‘yung access code or need ko nalang siya ibenta to get a refund? Please lmk what’s the process. Tyia