Policy Bazaar - Policy misguided

I had purchased policy for my mother from policy bazaar but they had misguided me while buying it. They told me clearly that for next * years, the premium amount will not change in any case and only after * years there will be any change in premium and it will fixed again for next * years.
Now, every year they are increasing the price saying that the insurer has increase the price. I told them clearly that your excetuive of sales team told me clearly that it will not increase in any case but they are saying that the excetuive which has told me that had left his job and I have to pay the increased price every year in order to continue this policy. They had checked the call recording and Firstly they had told me that yes his excetuive has misguided the case but we cannot do anything and now he is saying me that he has clearly give me the clarity on this. I request you to please call me that I can clearly explain the issue.