Blu mobi device permanantly out of order

We have our own coffee business and we are still new to the industry. We opened a business account at Standard bank and we also took the blu mobi device which Standard bank encouraged us to take as it works well for small new businesses. From the beginning we ave been struggling with the blu mobi device. Sometimes it works 100% but then it will just stop working for some or other reason. We have lost countless transactions because of this and there are very seldom someone that can assist us with any technical faults regarding the device. As a business we are trading after hours as well. We had a problem with our blu mobi device again on the 1st of April 2016 which is on of our busiest days of the month. I have tried to get assistance from Standard bank but the only comment from them was that they are closed and no one could assist me. This \unforseen\" difficulty with our blu mobi device happened to be on our busiest time of the day and there is absolutely no one that could assist us. Our business still needs to go one and we had to show many customers away because of a technical issue on our blu mobi device. As a new business we cannot afford but publicity like this."