Woocommerce app stopped working. Business shut down!!!

I run an online shop, and on the checkout page it calculates courier fees using the courier guy app, and then the customer can checkout. 2 months ago I hired a technician and paid him R1000 to install the woocommerce app for me and get it to work on my website. Today I realized that the app is no longer working meaning that my entire business is currently shut down and my income is cut off. Please get back to me urgently on what is going on, this is very serious as without my income I cannot survive or pay my bond anymore. I don't know whats going on but if you changed the app, then this is very unfair to do this to your customer without giving them prior notice. As this is going to have dire consequences on my business and survival. MY SURVIVAL INCOME IS CUT TO R0!!!