premium increased without claiming or notice given

Beginning of August premium was increased without notice given. Spoke to agent and decreased premium. On the 6th of August more money was deducted from bank account without notice. Complained once again and informed that because my marital status changed my premium was increased even more. How it this possible. My previous insurer never increased my premiums. If I claimed yes, I can understand that the premiums will be increased. But how does the fact that my marital status changed influence my premiums. I am very upset. I agreed to a new payment of R464 not R545 and according to the insurer everything is on tape.