Double debiting of cards

Spanish Visa applications... Do not pay them with a Debit Card or Credit Card. After Visa application was done and I paid via Debit Card, the following week on checking my account statement I realised they had double debited. Usually a business knows when they have more money than they should and would contact you to inform and re-reimburse. After numerous emails they say they will be a supervisor to call and sort it out but after a month nothing. This kind of business practice needs to be sorted out.