Someone please assist!!!

I took out a data contract at the Flash Cellular Vodacom store in Constantia Village in Cape Town on the 4th September 2019. The package consisted of a data line and a home HUAWEI modem. I used the modem for three days & then the 50gb data was depleted. I then never had use of the modem and I wanted until the 01st October to access the reloaded data. I could not gain access to the internet but the data was lost. I then logged a complaint with Vodacom & they replaced the lost data. Within two days, the modem stopped working. I then took it back to the store where I bought it from to have the modem booked in for repairs. The repairs department reported that the modem was irreparable and that they would replace it. It is at this point that I was outraged as Vodacom did not live up to their side of the agreement. I requested for my contract to be cancelled. On the 16 October I called to enquire about the status of my cancellation request and the agent advised that I contact the repairs centre to confirm that the modem is in their possession. I did that and provided them with the job card number and the agent promised to call me within 24 to 48 hours. It is now December and I still have not heard from them. An employee visited my home a month ago to persuade me to take out a fiber contract but I declined due to my experience with Vodacom. He then promised to assist me in having this matter resolved so that I can be ported to a fiber line. He is now avoiding my calls and does not respond to my emails. I called the contact centre yesterday to follow up and they advised that I should have the irreparable modem in my possession so that they can arrange to collect it before they can consider cancelling my contract. I called the repair Centre to arrange that I collect it, only for them to inform me that it is at the Huawei manufacturer and that I cannot get it back. I call the contact centr again to inform them and they say that they can’t help me unless they get the irreparable one. So what do I do now??? Do I drive from Cape Town to Midrand to go and collect it myself or do I just continue paying a contract that I have no benefit of?