You mean you paid money to have your machine cleaned of viruses and they sent it back to you with an infection? Ummm... You might want to find another computer repair shop.
Most shops reinstall the OS as it's simplest and fastest way to get rid of malware. However, if you want to go through all the steps, there are some websites that will walk you through it. This link explains what this malware is and how to get rid of it. Remove Longfintuna
Bleeping Computer is a great website to get help for removing Malware and Smartest Computing is another one. Broni has saved my bacon more than once and I think he is at both websites.