I guess I would have to ask why you think this. I checked out their website and their affiliations and there is nothing to indicate there would be an issue. They are partnered with Bank of China and Standard Chartered Bank, both of which are well know and reputable companies in financial marketplace. I admit there are some issues with their website, in regards to English. They have offices in Shanghai and Shenzhen, even though their headquarters is in Hong Kong, so this speak a lot about them. They don't have an office in Beijing, even though Beijing is the capital, it is not a center yet fully for commerce. Shenzhen, while located near Hong Kong is one of the leading industrial cities in China. Shanghai is one of the largest port and financial cities in China. Hong Kong is the leading city outside of mainland China where most financial firms are located. Hong Kong takes security seriously, in many ways more so than Beijing. Your English is actually Chinglish, so I must suspect that there is an issue here you are not speaking of.
Your punctuation is without proper spaces and your verb noun placement also signals you have an IELTS level of 3.5. Saving a card number in their database is not really an issue. It is there security software which a person should be concerned about. If you have actual proof of violations then please go to the VISA International website, which has a Chinese language version (中文.) for you to use. (你知道了吗?) I am certain if you can prove your accusations they will do something about it! If this is just an attempt to get them closed because you have a competing service and are trying to use a smear campaign, then remember that you did not actually pass that Cross Cultural Communication's class, you just simple attended it, so you did not learn that Westerners behave much differently! If this is just because you have some petty anger with them, well consider this is not Weibo and it won't mean as much here as it would there.
If you want when I am in Shanghai later this year, maybe even for Spring Festival, or Hong Kong I will visit their offices and speak with them about your concerns. If you are truly concerned I can have some of my friends in Beijing who have very good connections investigate what you say. I will pass on your post to them if you like! Remember, not all Chinese companies are bad, I know many which are good.