Ridiculously high maintenance for the shop

In my society, there are 25 flats and 15 shops. The maintenance charge for the flat is 5000/- per unit regardless of the size of the flat, however, the maintenance charges for the shops are based on the sq ft size and it comes to 7200 for the shop. However, most of the facilities (gym, lift, housekeeping, parking, security) are of no use to the shop owners. I had objected to this high maintenance for my shop in many AGMs but because of the minority, it was overruled. Because of this, I stopped paying maintenance for the shop. After that, the society stopped providing the only amenity (power backup) for the shop. Now they are asking for full maintenance for the entire period without providing all the amenities. What is the law in this case? 1. Shouldn't maintenance be common for all the units including flats and shops? 2. Most of the amenities are of no use to shop owners, can shop owners ask for less maintenance than the flat in the AGM? 3. AM I liable to pay full maintenance without getting the facility for the due period? Can I ask for the waiver legally?