Don't come back to rectify incorrect installation

On 24/06 Pieter from CKA Enterprise installed washbasin for me. Initially, was told that they usually charge about R420.00/hour for labour. But I happily paid R650 cash for the installation even though it was less that an a hour. Thought I would get good service, like their website says - 'It is our sincere commitment that we want to not just meet, but far exceed our customer's expectations when it comes to customer service &amp