Netshort Free Trial Weekly Charges - Refund Request

I had signed up for the Netshort audiobooks service, which was presented to me as free. Despite this, Netshort has been taking 19.99 per week from my account ending in 7357. I canceled the plan and removed it from my phone, yet they continued to withdraw money without my permission. I first noticed the 19.99 charge on the 23rd, and another amount was withdrawn again five days later on the 28th. I have tried to contact Netshort, but their contact options are not working and I have not been able to reach them in any way to stop these withdrawals. I request that all amounts taken from my account for this supposed free Netshort audiobooks plan be fully refunded and that my subscription be completely canceled so that no further money is withdrawn from my account.