Debit order charged twice

I purchased the App online for my daughter to improve her Afrikaans skills - I took out a year’s subscription for R719 in July. In September I received another debit order off my account for the same amount. I immediately contacted them to tell them they’ve charged me twice and their response was they can’t help me I must go via Apple or to my bank even though I showed them proof with my bank statements and the reference numbers. Very bad customer service and I will never recommend.