Corporate Invoice Question Regarding Dyson's Cordless Vacuum

I purchased a cordless vacuum cleaner from Dyson's official website on July 31, 2023. I requested a corporate invoice and filled out the necessary information. However, the company issued a separate invoice but did not send it to me. I became suspicious after ten days of not receiving the invoice via e-mail and contacted customer service. They admitted to generating an individual invoice by mistake and claimed they couldn't correct their error because I hadn't notified them within seven days. I am pleased with the product and have not returned it because I have already used it. However, Dyson refuses to make amends by canceling the old invoice and issuing a new one. I lost 3500 TL (Turkish Lira) as a result of Dyson's seemingly simple error. If a major corporation like Dyson is willing to expend effort to correct a seemingly minor error of 3500 TL, I have no problem pursuing my rights through Consumer Arbitration Boards and any other relevant authorities.