Midnite Sun & Cruise of Grand Rapids L.L.C.

After cancelling my membership with Midnite Sun and Cruise, I was charged an additional month. They refuse to refund, despite having proof of cancel.
I signed up for a membership with Midnite Sun and Cruise back in November, with my first charge going through on 11/08/2013 for $27.50. At the time I was told my credit card would be charged twice, then I could cancel before the third charge. However, when the time came to cancel in December for the third month of January, I couldn't cancel online. I contacted the store and was told the first payment didn't count as it was considered an "in-store purchase". I then had to pay for a third month of January for $65.99, but cancelled online as soon as I was able and believed I was finished dealing with this business. However, February came along and I was frustrated to see another charge on my bank account on 02/12/14 for $65.99. I called their customer service line, where I was told I would be issued a refund within 7-10 business days. After several weeks passed without a refund, I called again on 02/28/14. The lady on the phone said that my refund was denied. When I asked why, she said there was no explanation written in the comments. I asked why I wasn't contacted to be told my refund was denied, and she again had no explanation. I went into the tanning salon and the lady at the desk said I'd have to come back later when there was a manager. After making an additional trip to the salon later in the day, the manager said that their system showed my membership wasn't cancelled, so therefore she wouldn't issue me a refund. I showed her a copy of my cancellation confirmation email, but she still refused to refund as she repeated that her system said I hadn't cancelled. I've done everything I was supposed to, yet they refuse to do their part. I cancelled with them and didn't receive any services in February, yet I'm still having to pay for February. I wanted to be done with this company on December 31. It's now almost March and I'm still dealing with them. I just want my refund and to be done with them.