Email address harvesting by companies as part of returns policy

Companies use a returned product as a good opportunity to gather valuable customer data in the process of authenticating the return seeking to weed out fraud. Historically this would entail providing a name and address but in a digital age this has now extended to include email address. Rather blatantly companies are using this harvesting of email details to immediately add you to their mailing list and then sell on your details to associated companies. Unlike most forms of personal data collection there is no box to opt out of this and you are by default then subject to this and the corresponding flood of promotional emails that follow from the offending company and any related organisations. This process can happen fast as well with your personal details swilling a around within 24 hours the customer database of all many of suppliers. There is little you can do other than to unsubscribe from each of the email intrusions retaining control of your inbox. Not a very customer centric experience and far from epic