Refusing to release my line

I’ve been with level7 since September 2020 things went smooth except for their ridiculous reconnection fee and this year 2023 May I had financial challenges and couldn’t pay so when I paid on the 31 May our internet was reconnected. On the 12 of June I was disconnected and when I called to let them know that I just paid my account with their reconnection fee I was told that the amount was for May, ‘ but how because I was disconnected the whole month’ I then wrote to them the same day 12 June, telling them I no longer need their service so please can they release the line and the promised to release the line on the 15 of July which they have not done but have invoices me for June and July. And have also sent some lawyers to call me and when they heard the story they never contacted me again. Now I cannot go to other internet providers because Level7 does not want to release my line.