What happened to the “triple lock”?

In the 2015 Autumn Statement (https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/479749/52229_Blue_Book_PU1865_Web_Accessible.pdf  at para 1.133) much was made of the increase in the basic SRP by £3.35 pw, and the “triple lock” mechanism used to calculate SRP rates.

This weekend I received a notification of my pension uprating from 12 April 2016, and noted that although the basic pension has increased, the additional pension (SERPS) and graduated components have remained the same.  Since I began to receive my pension, only once before, in 2010, have these components remained static.  The overall effect reduces the percentage increase considerably below the promised 2.9%.

I haven’t been able to find anywhere, other than the BR2189 leaflet which arrived with the uprating notice, where the freeze on additional and graduated pensions was publicised.  Even then, it’s only obvious by omission, and when compared to the previous leaflet.

Have I missed something?  I feel somewhat cheated, and so will many others.  After all the additional components were “paid for” via NI contributions.