Disgusting service and Consumer rights violations from iStore Cresta Shopping Centre

I'm disgusted at the service I received from istore cresta shopping centre. I've been to their store trying to get the R 199.00 contract for 24 months on a Pre-owned iphone 7 for more than a week as advertised on the following link: https://www.myistore.co.za/discover-iphone/preowned They have been telling me that the deal is not available when it is clearly on your website. I have email correspondence as proof of trying to get this deal and guess what, the offer has now gone up to R 219.00 and they are still giving me grief. Is this how Apple treats customers and potential customers? I will be taking this up further with the relevant authorities.