Bad experience

I did some computer work for this company, and they promised to pay me. It has been a few months already and they haven't paid me. They don't answer their phones, don't respond to WhatsApp messages, and they have now taken down their website. I even went there to ask for my payment, and I was promised to be paid the next day. Then they said that they hadn't got paid. Come on, this is a big company with lots of money. My account was only R 1850.