I work as a bank/casual worker so basically zero hours contract and work whenever I’m needed if I can do the days they need. I do sleep in shifts. Next weekend I am down to do a shift that ends with a sleep in. I now cannot do this due to a family thing coming up (have to drive 2 hours In the morning to my gran to take her to a DR appointment, she lives alone and no one else is able to do it). I have emailed one week in advance to explain this. And been responded to with a very short, sharp email saying it is my responsibility having accepted the shift to find someone to cover it. I am happy to try my best by contacting my colleagues but if not possible I still can’t do the shift. My coNtract states nothing about this responsibility and I have never done it in the past.