REALGOLDSOFT BAKU AJ Ripped me off by charging my bank card for addding bogus security system to my computer, Alaska

Yes you were juped, since you changed your card you should be fine now though but the thing is the trojan it warned you about is actually Malware, Malicious Software composed of several types of viruses and their goal is to embed themselves into your computer and can do sever different things.  They can track your computers avtivity, reporting their findings back to the person who infected you. It can also send you to certain websites when you use your browser and also alter your search results when using search engines. 

My advised is to ensure all infections are gone from your computer, since anti-virus software isn't designed to detect all forms of Malware you might still be at risk.  This is why every computer tech uses a program called "MalwareBytes anti-malware" in the event of an infection.  You can download the free version at malwarebytes.com and as long as you update it after downloading it will detect and remove any remaining infections.

Also the only way to avoid this from happening is to use a dependable Firewall, make sure you have a firewall and that it alerts you whenever your computer installs anything.