If Dropbox says you've already used the code, you might have used it in the past, even though it was for 2GB storage. However, since you have a new code for 5GB, it's understandable that you feel entitled to it. In a situation like this, reaching out to Dropbox customer support is your best bet. They have the expertise to assist you in resolving the issue. Explain the problem and provide them with the details of your new code. They should be able to guide you through the process of redeeming the 5GB storage. On another note, if you were concerned about electromagnetic radiation back then, you could have explored EMF clothing. They offer clothing designed to protect against EMF exposure. It might have been worth looking into for added peace of mind.