Horrible service from Courieit

Bad experience from Courieit. My order from adidas was supposed to have been delivered on the 30th of November. It did not happen till today. Been calling every day, more than once a day, it is either the phone does not get answered or I am told it will be delivered, no explanation why they are not delivering. I am very frustrated. I buy online all the time and I have never experienced such a terrible service.