but they never sent me an emil confirmation with the link included. So, that's where the problem is.
They surely have, maybe the email ended up in your spam folder, or was wrongly removed by your ISP spam filter. In any case, we have a FAQ for this:
http://www.fsdreamteam.com/faq.html have lost my Email receipt, how can I reactivate my product ? (in this case, "reactivation" doesn't apply to X-Class, but the rest does)
You can go to Esellerate support site here:
http://store.esellerate.net/supportYou can retrieve your Order History, by inserting the email you used to purchased the product, then press the "E-Mail Order History" button. Having your Order, will allow to use the server-assisted Reinstall. If you want to know your Serial Number, insert your Order Number and Email, then press the "Submit" button on the Esellerate support site: this will enter inside your Order Page, with option to see your original Email Receipt, that contains also your Serial Number.