Misleading pricing on email communications

I received an email from Grabit after recently joining their mailing list. A table was advertised at R50 and when the link was opened, this price changed to R799. I communicated with online support who attempted to use their terms and conditions as a defense against their clear error in pricing. This is not covered in their terms and conditions and any other reasonable business would have taken the loss to safeguard their reputation and integrity. At a minimum they could have sold it at cost. Not impressed.