Vodacom - The Quest for Zero Clien-service

In Feb/March 2019 I signed a new Data agreement and also purchased mobile WiFi modem at the time. Lately I've experienced connection problems and upon investigation noticed that the battery of the modem was extremely hot and swollen and "ready to pop". This is the 1st time since 1992 (nearly 30 hrs) of. Using cell phones and associated equipment, that I have had this problem. I visited various Vodacom stores and other outlets they referred me to, to sort out this issue. I'm told that I have to go to the Vodacom store in Canal Walk (Cape Town) and hand-in the battery at their technicians, who will investigate the battery to see if it can be fixed. Anyone knows you cannot "fix" a cell phone or mobile modem battery. It needs to be replaced!! It's as simple as that. Period. I was informed that there is a 2yr warranty on the modem (battery included?). Why can't any Vodacom store upon looking at my contract and the state of the battery, simply exchange the battery and resolve the issue?! I rely on Internet connectivity for my home-based small business. Please, can someone at Vodacom resolve this Serious issue without further delay?! Right now, the service is poorer than poor. It is terrible. Abraham Lincoln said: " The buck stops here". WHERE does the buck stop at Vodacom AND WHEN?