This particular attack is more sinister and harder to remove than simply using good ol' Malware bytes to tackle it inside of Windows.
The software has genuinely encrypted your files. It's not a bluff to scare you in to giving them your money, nor is removing their ransomware completely an easy task. If you've got a data centre and 100,000 years, you might be able to break the encryption, otherwise you either pay them the money or simply take your losses.
There is one single, VERY small ray of light you may have at your disposal. But it may not work right away. After complaints are generated, the servers the criminals use are found and seized. Encryption keys are sometimes released in to a data base to help those affected.
How it works, is you upload an affected file and the server goes through the list of seized keys and finds the one that decrypts your file. You can then use that to decrypt the rest. The problem is, if it is an active operation you may need to wait a while.
What I'm saying is, your local IT won't be able to help you, but some of the data may not be a total write-off just yet.
By the way, if you pay them you are quite likely to get your key and the ability to decrypt your files. These ransomware criminals rely on their honest (if you can even call it that) reputation. If they had a reputation for non-compliance after payment, they would never make any money as nobody would ever pay them to start with.
It's a moral issue, do you pay the crook and take lose some money? Or start from scratch, take your losses and flip them the middle finger? Your choice.
EDIT: This ransomware usually infects your computer via attachments opened from email. Specifically, email stating you had an invoice payable or a resume to review and encourages you to open it. It's important office staff know to check addresses are from safe, verified sources before opening attachments and that all computer have an anti-virus and firewall. A central dedicated firewall is most effective.
