Revision in SFG schedule

I was told that the tests will be 3 days a week. Why has this revision been done? 

I had planned accordingly because I'm already enrolled in an optional test series which is going to finish by January end. 

3 days a week was manageable, but 6 is not. I can't sacrifice optional. Also, I have taken admission in SFG now. What do I do? Please suggest.