Unable/Unwillingness to assist client

I recently tried to cancel my gym membership with gym company & I followed the instructions provided to me, however I've been unable to finalize the cancelation due to no response from their support email. I tried to validate/re-register on their app, however the app is also proving an ineffective tool. I'm on the verge of canceling my debit order, should Gym Company not respond to my email regarding cancelation soon