Bad customer services at Supersonic

This people I asked for advice last year that I was moving places but I will be with no place for 1month and I need to cancel my Fibre subscription in November, they never even given any advice how to do it it was on the 27th of November 2019,they just said I must move with my Fibre. Then on the 20th of December 2019 I chatted them on WhatsApp to find out if they can install it at my new place month end of December they said they are on break they will be back on the 13th of January 2020 , I then asked them if they had canceled the subscription from old number they said the line was still on but they will put request for me a late request for old line to be cancelled, but I have to request it myself too I did what the person who call me to do but guess what still 8months down the line the line is still on and they want me to pay for the line I've sent an email to them to cancel,,, this people are charging me for two lines and 1 person is not allowed to have two accounts with different addresses is what they told me in when I app**** for my old line as I wanted to apply for my cousin ,, I will never pay for the old line as I know it was cancelled, I will only pay for my new line , Supersonic they are very bad when it comes to customer services no advice no nothing ....in February still I told them about the cancellation they said they will look at it but hey they continued to bill me for my old line and worse part the new owner wants to use the line but they are still holding on on it and keep me billing me for it ...and they never even called me to asked about the line they just kept quiet and kept on billing me..I will never pay for that old line .