DISREGARD THE CONSUMER PROTECTION ACT

I purchased a UPS from Takealot which had to be returned as it was faulty within the warranty period. Takealot credited my account advising "unfortunately the item you wanted is not available" which is not true - I checked the website... Further they credited my account without first asking me wither I wanted a refund to my account, a replacement or a credit as is my right in terms of South African law. I called Takealot to inform them that I wanted a replacement unit even though this was what I had informed them when I returned the unit, and the agent informed me that because it is now more expensive and the original supplier is out of stock, they credited my account. I checked my invoice and it is a Takealot invoice, not a supplier invoice. I asked the agent to send me a replacement unit and again she said they credited my account because the unit is now more expensive. This is a direct contravention of my rights as a consumer.