Bally Total Fitness, Bally Continues to Bill Even After Cancellation South Norwalk, California

I cancelled my membership at Bally Total Fitness several months ago.  Shortly afterward, I received a bill for $29.99 (one month's dues).  I called Bally to correct this, and they said that they did in fact have recorded information that my membership was cancelled, I did not owe money, and that I should simply ignore the bill. 

Three weeks ago I received another bill, for another $29.99 plus a "past due" $29.99 for a total of $59.98.  I sent them a letter asking them to correct the problem and send me written confirmation that the error has been corrected, but even now three weeks later I have not received any response from Bally.  I would definitely NOT recommend anyone do business with Bally or sign up for a membership with them in light of their erroneous billing practice.