Unprofessional and worst customer service

I purchased a product from Mr Shopper on 13 November 2020. Delivery was scheduled for 23 November 2020. Based on the tracking details, my purchase is no where close to being delivered. I spoke to a call centre agent on 25 November 2020 and they confirmed it would be delivered today, 27 November 2020 before 12:00. I have tried calling them but their phones go straight to voicemail.