Trying to cancel membership

I've been trying to cancel my membership with DW fitness and told by the gym at Glasgow Forge that I need to ring the number.  I have constantly tried and no one answers therefor I have cancelled my membership DD as I haven't used my membership for almost a year.  I had a call from the Forge to say that I will still need to pay my membership for March as I haven't spoken to anyone at the number given but no one answers.  I refuse to pay them any more money as I have tried my best as they only have one method of cancellation via this number but no one answers.