ConvertCart UI User Experience Designer interview questions

I've applied through linkedln. The next day got a call from hr and they asked me to come F to F but have told them. I would be able to come only on weekends she replied me we will send you an assignment after the completion of assignment we will get back to you. Have spent my whole day to complete the task and after sending there is no response hr is not lifting the call. This how you will treat candidates??