Spice Jet Airlines — baggage weight and terminal change

I am student traveling from jaipur to bagdogra via delhi in spicejet. Both my tickets are booked under the same pnr but there is a terminal change. All the other airlines transfer the luggage for connecting flights on their own but for spicejet i am asked to collect my baggage again and recheck in in delhi. How can you guys harass your customers so much.
This is not it. My baggage weight was 15.6 and a spicejet staff at the check in counter in jaipur named mohammed hassin was asking me to pay for it. Like common 0.6 kg extra is something all the other airlines allow. I had to reopen my entire luggage and remove stuff to bring it back to 15kg. Horrible experience in spicejet. Never travelling again in spicejet