Phonepe - Phonepe is deducting money wrongly and never bother to reply with logical response

as per phonepe Terms & Condition,in case of any return in myntra,cashback will be given prorata basis(see attchment) .As per myntra they have credited Rs.*** for my last return(see attchment)..
now the problem is:
placed oder values : ****.**
got cashback : ***.** ( T**********************)
returned values befor adjusting cashback: ***.**( P********************** )+ ***.**( P********************** )+ ***.** ( P********************** )
after return order value : ***.**

here the problem is phonepe adjusted the whole ***.** cashback where I am still holding order of Rs. ***.**.
for P**********************, cashback adjusted INR **.
for P**********************, cashback adjusted INR **.
for P**********************, cashback adjusted INR ***. here adjusted cashback should be **, so that the cashback will be applicable for remaining order of ***.** which I am still keeping.
they don't even bother to give reply properly.