That's why when a policyholder buys a policy, he should understand what makes up the contract and understand the various T&Cs in the contract.
The above looks like a loose sheet of paper. Usually only the stuffs that's legal binding will get bounded into a book - Policy Schedule, Policy Wording, Application Form/Declaration, Endorsement. Some companies consider official letters signed by authorized officer as part of the contract, some do not.
From the above picture, looks like it is a loose sheet of paper and there's some possibility that its not an official letter by the company.