Dear Mitesh,
There is some solution from thread,may be usefull.
How to delete requests not approved - AC 10
If canceling the instance does not work you can abort via se38 program named GRFNMW_MANUAL_INSTANCE_CANCEL where “External Key Displ.” is the request number for the MSMP Instance ID field.
I’d try the “1st try regular cancel” first and if that doesn’t work I use the “Directly abort instance”. Also make sure to enter text in the reason field
Regards
Baithi