con a ransomeware maker

[Theb]

Even if they gave you a decryption key there is no guarantee that your computer is really clean from any kind of malware, virus, or malicious software left by the ransomware. They might still be monitoring your computer after your device has been unlock in order to steal more from you. You should consider your computer good as gone and if somehow you have retrieved some files from your device you should assume that it is compromised by the ransomware. The only way to retrieve your files is if you have back up your computer before the attack even happened.

[BitcoinSupremo]

Don't want to sound harsh but this is totally your fault if you have not made a backup of your pharmacy data. I can understand that as a pharmacy you maybe not computer literate but that does not mean that you should have not pay a small amount to an IT person in order to make daily, weekly or monthly backups of your data. Sorry for your loss but if you don't have any backup there is nothing you can do.

[khatarnak]

If ransomeware had a timer i think you are done right now  
If your system is still alive check the massage box and Compare it with famous ransomwares massage boxes.
Most people using Free opensource ransomwares this days and most of them have a backdoor created by the coder of project.(because they are for educational purpose)
Check "hidden tear" on the internet and maybe you could Learn more about it.