Ex-husband not paying maintenance on stipulated date

Hello Curious one,
After going through your query, I understand your concern regarding the maintenance issues you are facing and here I am to provide you with a bit of advice:
Firstly, Section 125 of the Code of Criminal Procedure (CrPC) gives you the power to move to the court seeking the enforcement of the order if the spouse (who is ordered to provide maintenance) fails to do so. 
Under this provision, you can file a petition regarding the recovery of the maintenance that wasn’t paid and also ask the court to order your ex-husband to provide maintenance as per the court’s order. The court has the power to issue a warrant against your ex-husband, compelling him to pay the maintenance on a regular basis and the court can also impose penalties or give an order for detention if the default is continued. 
Additionally, if your case is being governed by the Hindu Personal Laws, then you can also seek the court stating the provisions of the Hindu Adoption and Maintenance Act, 1956. Here, if the husband fails to comply with the order previously issued by the court then you can file a civil suit regarding the maintenance. 
Referring to the case of Bina Devi v. Sanjay Kumar (2015) would be best in your case as in this case, the court has held that there can be punitive measures against the husband if the default concerning the maintenance continues further. 
At the end, I would like to suggest you to file a petition for the sake of the maintenance and the legal order which was previously issued as per the provisions mentioned above