given the middle finger by woolworths

i have been given the middle finger by Woolworths. i bought my kiddies shoes and after a while i realized that the Velcro does does not stick. the shoes keeps falling off. i returned the shoes for exchange and it was done. i exchanges the exact same shoes. 2 weeks later i realize that the shoes were not good. this time i went to the store for a cash refund. now because i don't have the original proof of purchase . i am forced to accept the refund in a form of a voucher to buy from the store that i am unhappy with. that sound unfair to me. i was referred to the original store of purchase and they cant help. i asked them to trace the transaction with the bank card i paid with, they wont. the need the proof of purchase. i walked out of the store unassisted with broken shoes that my son cant wear. i called their head office and they referred me back to the store. i didn't see the need to keep the receipts. i didn't think i will need it. i don't their gift card. i need the cash to buy my son shoes else where. this is Woolworths Mamelodi crossing in Pretoria