Poor service from MWEB

My LTE router last worked on the 28th of November 2019. I lodged queries with MWEB on several occasions notifying them that the router wasn't working. It didn't work for the whole of December 2019 but they want me to pay for December 2019 even though the router didn't connect or work. I fail to understand why they can't check my usage to see if there was any data used between the 1st of December to the 31st of December. I even asked MWEB to cancel this package because it wasn't working but they didn't. When I called the call centre I was told to wait until the end of March 2020. Why am I expected to pay for something that is not working?