What to do for increasing interim maintenance

I have filed pwdv in year 2012 . that same year i have got my interim maintenance of 20,000 for me and my two kids aged 11 and 7 respectively. my protection order has not been passed yet . meanwhile my husband had filed and won the petition of visit to children in 2015(subjected to change if it hampers the children) .during his last two visit he was found to come drunk and embarass me and demean me as i have filed a divorce case as well in 2015. i have also got his salary statement by filing a rti. as i have two grow up children who studies in convent and have to bear huge expense am planning to place a plea to increase my maintenace amount . my husband is a manager in one of the navaratna companies under cental gov. but he has sensed my plans and tricking eg.( purchased a flat of 25 lakhs and few days back a new car of about 4 lakhs) only to avoid the situation. i m trying hard to secure a job for myself as well. as for the divorce case the 3rd summon has been sent on april but still he has not appeared . pretty confused. pls advice