Increase in premium of 17.1% after paying for 10 years already

We just received an email from Liberty life because we have been paying our life policy for ten years. To reward us for this loyalty they are increasing our monthly payment with 17.1%. They do not feel this is a high increase because in the small print is says they can increase us as high as 25%. So they have done NOTHING for the money they have received from us the last 10 years, paid no claims and yet they find it fair to increase our policy with such a high amount. The letter does say if we refuse the increase they will reduce our benefits accordingly and we will be covered for less money. What a thank you for 10 years of paying them money for nothing. Seriously sad and disappointed.