3 weeks downtime

In August I paid my account one day late. My internet was off. It took them 2 weeks to restore my internet. I was chatting to them daily had to reset my router everytime I spoke to a consultant. One of them promised me that I will receive a credit for the 2 weeks downtime. When I queried them I received a response that because it was not paid on time they cannot refund me l. Since the beginning of January have been having downtime on my internet. I started querying them go through to same procedure of resetting and nothing happened. Eventually 2 weeks ago it went down completely. I was told that the problem is with Vumatel and that they would come out and rectify it. On Friday the 20th Vumatel technician came and I was told that they will have to reinstall my ONT but I was told that I will have to pay for it. Nearly a month without internet which I paid for on time and still nothing. Will they refund me for the 3 weeks? And why should I pay for the reinstallation of the Vuma ONT when it was already installed when I moved into the apartment. You cannot get hold of them have to speak to Willie the bot and they take forever to respond. I am very dissatisfied with their service as there is a reason why I got internet in the first place but now I have to buy data every day in order to work from home.