size out of stock and refusal to refund/exchange

On the 24th my husband went to Woolworths the Grove and bought me a 2 sets of Underwear/Lingerie as a gift , On the 27th i went to the grove to change the bras for sizes as these bras were small made and was told they out of stock but i can go check at menlyn and i went to Menlyn on the 02/01/2016 and i explained the situation to customer services and was told by the manager on duty they will check for for bra sizes in all stores and they took down my details(she asked that Leah will take over my query. Leah came back to me on the 3rd and explained they out of stock on the bra sizes on one of the items but have managed to find one in CPT and it will be delivered and she also said she will advise the manager that the other Bra's are no longer available .i was called to come to the store yesterday 07/1/2016 as the CPT delivery had arrived, They willing to refund me or exchange bras as they cannot find my sizes and i am told their policy does not allow them to exchange or take underwear.2. ITS NOT THAT I DONT WANT THESE ITEMS BUT THEY ARE OUT OF STOCK SO WHOSE FAULT IS IT THAT THEY CANNOT ACCOMMODATE ME.THERES NO SIGNAGE IN THE WHOLE STORE REGARDING THIS POLICY, CASHIERS DID NOT INFOR