cotton on perks vouchers

good day. i have phoned the nr of the shop in the mall( no answer for days) i have mailed there headoffice(no reply) i have phone there customer care(busy leave an message we will phone back and wow surprise no reply). my complain is if you buy for R200 and use you perks discount or your birthday discount of R100 and you take back the item, they give you your R100 cash back but no voucher. they dont put it back on your perks card they dont override and dicount so next time you must pay the full amout so that means they keep on making profit??? that had happem to me twice now and the managet there just say they will put it on my card. i was there Sunday again they will put it on my card.. i mean that is not alot of money bit if they do that to alot of clienta how musy profit do they make on perks vouchers only? that is the only place my daughter like to buy and they know that. i have send someone a few times so they tell them to phone me back and still no phone call