Co-Operative Housing Society — non-occupancy surcharge on repair expenses

Address:

Pune, Maharashtra

My society is charging 10% non-occupancy surcharge on monthly maintenance bill for my rented flat. I am paying that surcharge.
Building is now undergoing some repairs and society is charging each flat to share the cost equally. I am ok to pay my share. However, society is also charging me 10% non-occupancy surcharge on top of my share of building repair expense. Is this legal?
I can understand paying non-occupancy for service costs, but why i have to pay it on top of repairs? Seems wrong to me