Vodacom horrible service and neglecting customer's complaints

I launched a complaint about Vodacom internet early this year and they promised to come and fix the problem only to find out around May that router doesn't connect to the nearest tower and they told me they will escalate the problem up until now I am paying every month but I can't use the router it's even worse from 13/08/2026 even the phone internet is lost. One of their sales agent called on Thursday 20th and I told her about the internet problem and like all of them she said she is going to escalate it. Who is supposed to fix the tower problem? Why are they selling us routers knowing very well it doesn't connect to the tower? If I want to cancel the router contract because it's not working they are telling very huge amount I must pay. Is it my fault that the internet is not working?