Seatbelts faulty, reported but dismissed…

I made the flight attendant aware that my seatbelt was not working before departing. When I tugged on it, it just slid loose and did not ‘kick’/ break. I repeated my concern and again she dismissed me (without testing it for herself). The scary thing is that the people next to me also tested their seatbelts and also did not work. I will not fly Flysafair again!