Spice Jet Airlines — Baggage Allowance and Charges

I flew on SpiceJet flight SG169 on Jan 23rd 2025 at 9:40pm flight from Delhi to Mumbai. I was carrying a laptop bag and carry on which the airline personal charged my 5850 rupees even though 1 free check in was allowed. They had an option to check in that bag but instead charged me for taking as a carry on. On the top of it when I was boarding the flight they forced me to check in even though I was told I am being charged since I am carrying on. So net net I paid for something which was free check in the first place and then not allowed to carry on. So why was I not excused and then charged and then suffer to go through check in.