I don’t agree with HMS.

This is the fact:
Based on ur nationality and ur own visa duration ur family visa duration is approved. u got 2 years which is fine, I assume from this u r from India or Pakistan or Bangladesh. Europeans get 5 years etc.

You just have to submit an extension application to Labour dept without having to go there. It will take about 3 - 5 working days for approval.

Don't worry it hardly gets rejected.