Can a life insurance company increase rate of premium arbitrarily during policy period?

Suppose I take term insurance (for life cover) for 25 years from some company since I find they charge lowest premium. Can it happen that the company hikes the premium rate arbitrarily after 5 years, to such an extent that I find the rate is more than the premium rate of some other company I ignored earlier. Is it better to stick to public sector insurance companies or are they as good as private sector companies?
Thanks for the reply. However I am more interested in the current situation in India.

Why Introduction is must for opening an account in banks?

Al most all banks ask an introducer to open a account in their bank. The introducer may be of any type. Actually the banker may not be knowing the introducer in person. But his signature is honoured. Why, what is the logic/ reason behind it. Can any one clear me?
Is it applied to all like ministers, governors , secretary’s, etc ?