Received expired product from spa ceylon what can i do.

I have ordered 2 products from Spa ceylon website on 02-12-2016, one product was discounted and other product was of very low cost but without any discount. I did the payment online.on 03-12-2016 i got a call from the company employee that the low rated product was a actually of a higher cost and was a technical mistake on website, hence we will cancle this product and can send only one product, after few arguments i agreed for the same and requested a credit note for the extra amount i paid. on 07-12-2016 i received only one product that too was expired, also i didnt receved any credit note. i confronted them on the same no. about the issue the female executive informed that if it discounted you will receive expire or near to expiry products. i questioned about how can expired product be send and i need a replacement on which she said she will ask the concern person to call me back. what step should i take if i dont vet replacement and what about the other product that they cancelled?