Question about OKI 46857508

Hello digitec I bought a black OKI image drum 46857508 on 21/08/20. It was already clear from the first printouts that something was wrong. There are white dots (approx. 5mm diameter) on the printout, i.e. part of the text is missing there. To make sure that the problem was with the image drum, I ordered the same part again on 2 September 20. With this part, the C824dn no longer has any problems at all. This means that the problem is with the image drum. As I do not have a digitec guarantee for this part, please give me OKI's contact details. mfg