All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
All kinds of insurance contracts are unlawful. In fact, these contracts include risks and hazards as well as eating people's belongings without a legal right. The person could, for instance, have an accident, or an incurable disease right after having concluded the insurance contract. The treatment of this disease could require paying installments over many years. So, how would the Muslim accept this money which he has not deposited and does not deserve legally? Similarly, the person might not get sick during a long period and spend all this time paying installments for no right purpose.
The scholars are all agreed that the non-Islamic contract is invalid, and each one of the two parties should take back what he has paid. The evidence for this is the verse in which Allah Says (what means): {… but if you repent, you shall have your capital sums. Deal not unjustly (by asking more than your capital sums), and you shall not be dealt with unjustly (by receiving less than your capital sums.} [Quran 2:279]
So, what you deserve of this insurance company is an amount equal to what your father or another party acting on behalf of him had paid. If you believe now that what you have received so far is equal or more than what has been paid, then you should stop getting any more profits from this company. If, on the other hand, you think that the amount paid (by your father or a party acting on his behalf) has not been consumed, you could carry on profiting from this insurance until you recover all your rights. But know that any amount you take more than your right is considered as eating people's money without a legal right and consequently it is forbidden.
Allah knows best.