it says 24 months yet you more for 25months

I have had the worst 2 years of experience with Cell C, my 2 year contract comes to an end on the 04 November this year and they want me to pay for the entire month of November. I made contact with them on the 04 October to request for my contract to end on the 04 November spoke to the retentions team and they initiated the process. I then called up last week and i was advised by Mpumi from the cancellations dept that the customer service dept can pro-rata my allowance and the amount i should pay she passed me then through to Jauhara in customer service dept and was advised that she cannot do anything. All i require them to do is pro-rata the amount i should be paying as i will only use the service for 4 days. I opened up a complaint and got a call back after 48 hours from Debra in complaints she said they can do nothing to help i must pay the full amount and have to use all my allowance before the 4th, I was unhappy still as i should not pay a contract for 24 months, 3 weeks and 3 days. I escalated further and got a call back after 1 and 30 minutes where i was promised i would get a call back in 30 minutes, I spoke to the manager Nikiwe and she said i have to pay the entire month. Very Irrate.