Mechanical fault

I booked in my car as a result of a factory fault on my vw polo Tsi on the 6th of December 2017. On this date I was told that a part is required to fix this fault on the car and it would take about a week or so to order this part and I will be updated. 2 weeks later with no calls nor updates I constantly call for updates with no luck of being assisted. Today on the 3rd of Jan 2018 I am being told that hopefully I will get the car end of the month and that the part was only ordered last week. I have never received such bad service in my entire existance. They can't even show me on paper proof that the part was ordered.