Do not trust makro employees trying to sell you extra things

I bought a gas hob and chimney, the salesman told me about a warranty extension that was R500 for 5years. I accepted it and he handed me over to a lady by the name of Jetaime to facilitate that process. The salesman emphasized that I’m getting the R500 extension. Now when I check my invoice I noticed that I was charged R710. When I call them to query, none of them are able to give me answers and they are saying this lady is not in. I feel like I was ****med and this is what they normally do. They said I should come instore when the lady is around as if I have the luxury and time to be doing this back and forth. I do not live around there and it is not fair that I have to be inconvenienced because of their dishonesty.