Bajaj Finserv — I want cancel my product

I ordered realme gray colour mobile through bajaj, by yesterday. But unfortunately the mobile shop doesn’t have the gray colour, so they told me to cancel and reorder the another colour. So can you please tell me how to cancel the order.. Why i cant cancel the order.?
Pls look on the message that i booked...

Dear prathish kumar k, thank you for using your emi card ending 9605 for a loan of rs.15999.00 to be repaid in 008 emis of rs. 2000.00. Transaction reference number[protected]. Available loan amount on your emi card is rs. 29001.00. Available open ecs limit is rs. 98000.00. To know about your loan details please click on
http://m.BajFin.in/MlisqGcE
Or to know where else you can shop click
http://m.BajFin.in/TQ33cZ5U
. Regards, bajaj finance ltd.