As per your concern, we want to inform you that Once you start creating more call logs (when you make, receive, or miss calls), your device will start deleting the oldest call logs you have on your phone.
When you run out of storage space on your device, the OS may automatically delete the old call logs to save space. you can see the call history information available on your device currently and if you have set backup you can restore the data. Rest if you want full call history, you can contact the network operator, they can provide you with better information regarding the same.
