Ridiculous MWEB after sales customer care!!!

I have LTE WiFi contract with MWEB. I reported that my ZTE modem switches off, and I work from home some days and I also need the WiFi for my camera, therefore when it keeps switching off it is an inconvenience. When reporting on the App, no one bothers to respond or action my query. Last week, I called your call centre, and I was told to troubleshoot, the person suspecting that the issue could be the UPS, that I also purchased from you. The next day I wrote on the app, informing you that the modem keeps switching off whether I connected directly from the plug or UPS. I didn't receive any feedback. On Tuesday, I called again, and spoke to a rude call centre personnel, who eventually assisted and advised that they'll be a swap. Today, 12 October 2023, the swap was delivered and I gave the driver the modem that was initially mine. The disrespect of sending me a dirty modem, showing that it's from another customer, that does not even switch off, showing that you did not even bother to test it. I would like to have a new replacement modem. I believe that the fees that I pay on a monthly basis covers for such defects. I do not appreciate it that you think you will save on my expense.