Money making scheme

My children were enrolled with these schemers early this year for computer lessons, Everything was fine and the kids enjoyed the classes, until Rinico computers did not honour their appointments, they missed most days which they were supposed to be tutoring. My husband constantly tried to contact them and he was given a runaround. No one wanted to give answers, the kids loved the lessons so much and it pained us that we had to remove them from the classes. And also made the school aware of our dissatisfaction. Now three months later we are receiving threatening sms with possible jail time if we don't pay the outstanding balance. Which One? Because the kids ceased attendance a long time ago, and they didn't even bother to find out why are they no longer coming for lessons. These ******* to even think that we used to pay 4 months in advance for services not rendered. We should be the ones demanding a refund not them. Petty ******. All they care about is milking the poor.