Veterans For Wildlife - Not honoring cancellation & refund request

I have been donating to the Veterans for Wildlife Charity since June 1st 2018 and requested the Charity stop deducting money from my account following my 12th monthly donation (01 May 2019) yet they continue to deduct money from my account, and after numerous requests, they fail to adhere to my requests for a refund of my most recent deduction, as I cannot afford to donate. They too have failed to send me my Section 18-A Certificate for tax purposes too after numerous (three) times of asking.