Samsung electronics

I have a s21 which I got in December 2020. Between then and now the cover over the top camera has a small Crack on it but the phone still took nice photos. On the 13th February 2022 I woke up at about 04.45 and checked thr time on my phone I then closed the phone up and went back to sleep. I then woke up again at about 06.30 opened the phone and it was dead. I went onto the internet with my tablet to see all possibilities of why the phone will not turn on. I tried all of them. In order to keep myself online I had to go take out a new contract with vodacom so I could make calls. I then took the phone to vodacom repair center in Durban and the told me that my garuntee was voided because of the small Crack on the camera cover. The phone is still in a very good condition except for that small Crack. The phone does not want to switch on because of it been defective and not because of the small Crack. Samsung should still cover the warranty of the phone. When you request for a manager at Samsung headoffice to call you they don't. I was on the phone today for 45 min waiting to be put through and nothing.