No confirmation from Plant Fitness re: not renewing my contract

I've sent various e-mail to Planetfitness regarding my contract which ends, end December 2017. Asking them to sent me written confirmation that the contract will end, end December 2017 and will not go ahead on a month to month basis. I've also requested them to do the necessary and confirm that the last debit order will go off on 15 January 2018.

To date, I've received one phone call asking me why I do not want to renew my contract. After discussions I've asked the member of Planetfitness to sent me the confirmation which I've requested.

To date, no confirmation. Why don't they want to confirm in writing that the contract will end, end December 2017 and that they will do the necessary to cancel the debit order.