I work at a software company too. My company addresses the issues promptly and we provide top notch customer service. If we can't fix it, we offer alternative ways to get the tasks done. We will refund unhappy clients.
I hope your clients are looking for alternatives. If our clients paid us and the software was broken FOR A YEAR AND A HALF, you bet your bottom dollar that they would move to a competitor.
Let me guess, your company doesn't have any competition?