NO After Sales Service

I purchased a Whirlpool Dishwasher on 26 November 2016, so it is still under warranty. Early in August 2017 it suddenly stopped working. I immediately logged a call with Whirlpool South Africa Service Department. They sent 2 technicians a total of 3 times to look at the dishwasher. They could not find the problem, but left it at that. I have contacted the technician several times as well as send emails to the Service Centre, asking them to escalate the problem or tell me what I should do. They do not respond to my e-mails or make any effort to retrieve the dishwasher for repairs. I am at my wits end at what to do. I have asked them to refund me so I can purchase another brand of dishwasher, but to no avail.