Very frustrated angry customer

I have been a very patient customer for the past year. We have been a Mastercare customer for the past +-15 years and have had a lot of patience with them. As the years progress the work becomes more shoddy as they use inferior parts/pirate parts. The service providers they engage are not qualified in their field of work. They send these technicians out about 2 to 3 times to come and look at your appliance to take pictures and send to them. These technicians do not even have tools to test the appliances but try their best to see what the problem is. We have made numerous calls to the call centre for help with the fixing of our appliances. We keep getting empty promises. My fridge and stove have been reported since July last year and to date the items are not repaired. They have sent their technicians to fit a new plate switch which is not a defy switch and have messed my glass top stove up 3 times. The double plate does not even work till today. I phoned defy and got the right part number and gave it to their head of their call centre gentleman... To date the part has not been bought and the stove not repaired. Their technician came here on Saturday to repair my fridge and put in some alien part. 15 minutes after they left the fridge was doing the exact same thing it did before they came to repair it. Please note we are waiting for these appliances to be repaired from last year July. We have paid these premiums faithfully but we get shoddy service. This is a very bad company to deal with they should get struck off as service providers as I have never seen such bad shoddy workmanship and lies in my entire life. They are quick to send emails and messages informing you the parts have been ordered and they are waiting for delivery. I am sure these parts must be ordered from somewhere overseas as they never arrive to date