CREDIT NOTE VALID FOR 30 DAYS??? SERIOUSLY???

I returned a blanket a few days after buying it in May and received a credit note for the R499.00 that I had spent. Today, exactly 5 months after receiving the credit note I went into the store and was told that my credit note had expired and that it was only valid for 30 days. The computer was not accepting the c/note number. The staff and I called the 'Careline" between 6 to 8 times. The instore staff were helpful and tried to get clarification but to no avail. This is a straight *******. Thank goodness my credit note wasn't for a couple of thousand! Nowhere on the credit note or in store does it give a period of validity. All the ladies on the 'Careline" could only repeat like a mantra that I had 30 days for a refund. When asked about the validity of a credit note..back to the mantra...even from the team leader! They have 'kindly' lodged a complaint for me which should be responded to within 2 to 3 working days! My time, money and petrol are of value to me but not to Loads of Living or Truworths!! Guys we just won an award for the best call centres in the world! What is happening in yours??????