Internet router never worked from day one

On the 10th September 2023 I ordered internet router with DStv multichoice via their contact whatsApp number ( +***8 ) and I was assisting by Thato. And it was delivered on the 15 September 2023. I connected it and it didn't work because they needed me to pay the Pro-Rata money which I did. Then it started working only for two days, then on the 18th i text them again on the same whatsApp number enquiring that my internet is not working due the network coverage and it only works for 5 minutes then reboot itself for more than 10 minutes, sometimes it doesn't work for the whole day. Then I was chatting to Hillaray who advised me to switch it off, rake out the sim card and reset it, of which I did but it continued doing the same thing. I then requested for cancelation on the same day, I was told that they send the query for cancelation and I will receive a call after 24hrs which no one called me.on the 22nd I then text them again and I had a chat with Teitumetse , explaining the same problem to her and she also advised me to reset it. I then requested for cancelation and she also said she has sent a request and I will get a call within 24hrs, of which no one called me. Then later on that day I spoke to Musa and he also promised me that he has escalated my cancelation request and I must expect a call later that day which was on the 22nd September 2023 or the next day, which till today I haven't any call. Then on the 26th September 2023, I text contacted them again with the same query of which I had a chat with Mary and I explained the same problem and requested a cancelation, she said to me " She logged a call for a cancelation due to lack of network coverage and they will contact me in the next 24hrs". Still no one ever called me. I decided to call thier call center myself on the 4th of October and I was told that my router is active and has data so there is no problem with it and if I want to cancel it I should go to my nearest DStv shop and they will explain everything to me and I will liable to pay them the remaining 23 months installments in full before I can cancel it. I don't think it is fair for me to pay for something that I reported within few days after it was delivered and also pay for something that doesn't help me at all. There router is Nonsense as it only works for 2 minutes then reboot itself for 10 minutes and sometimes it doesn't even work for the whole day. Kindly assist me to return DStv multichoice internet router back to them and cancel my subscription with them. Thanks.