Unsatisfactory service - *********** workers

Since November 2024 been trying to cancel my line, from April trying to change my LTE to fibre without success I went to the customer service branches and called the call centre no success, the retention center is not helpful, my last call the call agent was rude and she dropped the call I am paying for my land line which I did not use for months, all I want is for my landline to be cancelled and LTE to fibre, is it do difficult