Hmm... even Ishika's plan wasn't staged well. As if she knew Amruta will not close the bag while giving it back, few bundles will fall down, and she will hand it over to the guy. Yup. [Could've kept it closed.]
Shengdaana now seems to be pet name of one of the writers.
But making it so obvious - like encashing the cheque gives it away. Hope Amruta is not shown dumb.
Think Jayesh is in the arrest scene to point out how badly Amruta has chosen to be with her mom. 



They weren't good friends at all, just were turning bit more cordial softening towards each, slowly about to become friends during Lohri. 
Their insistence on revenge is only going to put them down further. 