Premium increase of R672 pm without communicating

Auto & General are such a bad company. Some insurers were giving their customers reduced premiums while it was hard lock down, nothing was offered by Auto & General to me. After that they secretly increase my premium for an amount of R671.85 increase, no email or call whatsoever regarding the increase. I have never claimed except for a flat battery call out once, the car value depreciates, we travel lesser. I want Auto & General to indicate to me what is the justification of such an increase of R672 per month, (for some that is an insurance premium altogether). Secondly proof of communication for such increase that was sent to me as I would have never agreed to that nonsense.