When co payment charged? Is co payment is refundable How to claim it back?

Co payment will be charged at the time of claim or as decided at the time of policy inception or buy of a health insurance policy because co payment condition vary insurance to insurance or paln opted by the insred and Policy holder,Sometime some policy holder decides to apply the copayment only on reimbursement or sometime it applied on both cashless and reimbursement, Co payment is non refundable amount if a policy has condition for co payment then that amount will be deduct as per opted policy condition and it will not be refunded.