Contract period

I spoke to Obert from Zone fitness on the 14 Novemeber 2017 when my husband and i took out the contract with zonefitness where he initially put down 24 months but than i told him the same day i want it to be 12 months instead and i messaged him via whatsapp as well to confirm that it has to be changed to a 12 month contract. Please see attached whatsapp chat where Obert confirmed it will be changed to 12 months instead. I want this cancelled immediately for both my husband and I as this is unacceptable. if this is not cancelled and i don't receive confirmation of it being cancelled i will take this further... We pay every month for the gym where half the equipment is never working!!!!