District administration is not paying my dues

TLDR: I worked with government officials; after work, they are not clearing my dues of one lakh. What should I do?

To keep myself private and safe, I'm using a temporary account. I'm new to Reddit and not familiar with its usage.

The district administration has contacted me regarding a course-related discussion. I have approximately 5 to 6 years of experience in specific digital skills. They told me to make a course out of it and teach it to the district people. I mentioned that I have no experience in teaching, so I'm unsure what to expect in terms of pay. They said they will cover my travel cost and 1 lakh for the whole course. I said okay, as I was free at the time and thought it would be a win-win to review the basics and get good pay.

I thought the course would last 1 month, and the pay is . I had some plans with the pay, which I can't disclose for privacy reasons, so think of it like I would buy some things and upgrade my living. I started teaching, so the number of students expected was relatively low, as expected from the forms and applications, but we have not discussed anything related to bringing students of my own, so I kept teaching, as it was my job, and the course took 3-4 months for 2 batches.

I thought I had some savings to manage right now, so I shouldn't bother them; once everything is finished, they will pay me. I was new to official work, having no prior experience in teaching or working with officials.

Now the course is done, and I asked them to clear my dues so I can finalize the to-do list or plans I had with the pay. They told me that the government has a rule that a trainer can be paid a max of 20k per month, so you have taught 3 months and take 60k. Even if I add only promotion and travel costs, I have invested 10-15k from my pocket, and the pay is relatively low compared to what I was earning through my work from home or digital work.

After asking them to pay what they had promised, and I think I deserved it, they started ghosting me.

Sorry if my writing is not understandable, as I'm a noob and kept some details for my privacy, as I don't want to be dragged by officials without any wrongdoing, so kindly help and guide me through this. What should I do in this case?