Ist nerdkudo.com sicher?

NerdKudo used to be known as GrabSmash. Why they changed, I don't know, but I have an idea. When they were GrabSmash, I had browsed their site, and nearly completed a purchase. However, I decided against it in the end. But in the process, I gave them my e-mail address during the aborted checkout process. This was a huge mistake. Because after that, I became FLOODED with spam -mails from GrabSmash. I would receive probably 5 e-mails a day from them. And every time I clicked the Unsubscribe link at the bottom of the e-mail, it would tell me that my address had been removed, and I was unsubscribed. But, the e-mails kept coming. Finally, I e-mailed their support, and they replied that my address had finally been removed. And the e-mails finally stopped. However, once the site changed from GrabSmash to NerdKudo, the e-mails resumed. So, their claim that my address had been removed from their system was a complete lie. They seem to believe that, simply because they changed their name, they are able to ignore any customer service promises they made in the past. One might even assume that they changed their name simply so they could pose as a separate company, and resume spamming those they had previously "promised" to remove. Simply put, this site is NOT TRUSTWORTHY. I would NEVER give these people any sort of payment information. DO NOT buy from them. They've given no reason to believe they're credible.