Inadequate finance system

I always thought that Miele is a respectable company however I came to conclusion their financial system is a mess. I paid for a service delivered at 22/10/2019 on the 23/102019. Yet, after several emails, I have been handed over to Brooks & Luyt company which also seems not know what is going on. After several emails and telephone calls, and showing them the proof of payment they still do not rectify their system. I just wonder what the mother company would think of this poor service.