Can I sue an App company for losing all of my company's clients and schedule data during a recent update?

I am a salon with over 500 clients.Due to the loss of data during a recent app update, I can't schedule any new clients in fear that I will overlap my appointments and I can't leave my company for even a second in fear of not being in my salon room for previous appointments that I already have made. I made it through last week based off of memory, hoping that the company that lost all of the info would have the problem fixed as promised but they still haven't fixed it and claim to be working on it still. If I have to go through another week without being able to prebook new appointments I will lose my opportunity to make new revenue. I'm at their mercy and feel helpless until the issue gets resolved which seems like it is taking may too long.