Hard to cancel

I phoned to cancel my membership in the beginning of November 2013. They said as I had just missed the first of the month , I had to pay for dec?!(cheek) So I paid my DD on the 1st dec and then cancelled the DD. Bearing in mind I had effectively given them 7 weeks notice, I have received a rather horrible letter telling me to pay for January £39.00 or Ill be referred to a debt collection agency!!!! I have telephoned head office to complain, and they said they would speak to the gym manager as I cancelled my contract legally. So basically it is the gym in breach of contract, as they made me give more than 4 weeks notice. I think it's me who should receive a payment. Picked on the wrong person this time. Adding to that, the opening times are rubbish 0900-1300 and 1600-2000hrs. Half day on Saturday and closed Sunday. You need not work and have no children for this gym to work for you. Would never go again!!!