Spice Jet Airlines — overcharged for extra bag/unethical behaviour

Address:

SpiceJet Ltd., 319, Udyog Vihar, Phase-IV, Gurgaon- 122016

I travelled from bengluru to gwalior with spicejet flight no. Sg 3325 with pnr zf827a. As per the policy, i was only allowed 1 check-in bag and 1 cabin bag. The weight for check-in allowed was 20kg and for cabin it is 7kg.
However, i had three bags due to long stay. The weights for each bag was as followed -
1. Bag 1-11kg
2. Bag 2- 15 kg
3. Bag 3 (Hand bag)- 4 kg
Therefore, the total is 30 kg which is just 3 kg above the allowed capacity. The woman at the airport check-in asked me to pay inr 5500 for 1 extra bag, i repeat 1 extra bag. The original price of my ticket is inr 4981.
When i spoke to customer care, they told me that i will only be charged for the difference or overall inr 2000 for 1 extra bag. The woman at counter very unethically and rudely told me to leave my bag at airport if i dont make a payment. Hence, i had to make a payment. Now i want to understand how the amount for 1 extra bag is more than 1 person's ticket. I was given a handwritten receipt thats all.