Pathetic company who ignore requests and do nothing

Have been trying to cancel a mobile contract for 3 weeks .Have spoken to 5 different people at Summer MOBILE being Sarah ***, Norma and Larah who all promised to sort out the cancellation.We requested cancellation 3 days after contact with them.The latest a supposed manager(Chaslin)was sorting out and promised to reply but when he did not we were told he is now on leave for 7 days.Nobody has done anything and we are just given stories that they will cancel but after 3 weeks nothing has happened.You cannot speak to a manager as they have none , I am told.