Is sitepoint.com Safe?

I was very active on that resource like 15 years ago entirely anyway. I do not know what is now here, but I am still getting a lot of newsletters from them absolutely and I do believe that something could really be worthy here on HTML, CSS, JS and so on.

Sent me an mail containing that I can download an ebook bundle which consisted 8 ebooks. I opened the link to download it. It took me to the website's cart page, I verified the website url and SSL certificates the reviewed the cart. Cart: There were 8 ebooks as it was told in the email, I then checked the price. The price for every ebook showed the actual price as it was without any offer but in the total the whole price was deducted to $0.00, I proceeded to checkout. Checkout: While checking out completly and before proceeding to the download page it asked me about some information, consisting of email AND CARD DETAILS. I, thinking that its just a formality, provided the details of my card (luckily the one that didn't had any balance). Then I was on the same page after submitting the form and the page showing some error that my card details were wrong, I tried again (for 6 times in total) and it kept on showing the same error message. At last I left the hope and closed the page. That was not it. I recived the call from my bank's head office and they said that last night there was an attempt for payment for the merchant 'Site Point Premium' California for 6 times but it didn't succeded due to insufficient balance (luckily). They have called me to confirm if was real and not frogery. I trusted this website until this. How can one charge if it is free of cost and when on checkout I am told that the balance is $0.00. It is a clear cheating with the customers.