Managing extra workload and the feeling of being underpaid

was having a lot of problems at the sites. The Dealer first used to deploy contractors at the site but later started using manpower [to save on the cost of contractors]. I was managing 6 sites at the same time. I used to travel almost 150km daily. I put in my resignation 3 days ago and am currently on a notice period. I had achieved 90% of my targets too. However, I’m not getting paid as per my efforts. My expenses [mainly in traveling] are more than my salary.