Blacklisted licence even after promt payment

I had bought the Parallels for Mac under a student discount for a subscription of one year. I had provided proper bank details and the payment was made. But for some unknown reason the amount was refunded and an email was sent regarding repayment. They shared a bank detail and I made the payment the same day as soon as possible. For proof, I have my bank statements which clearly show no delay in payments.
Even after that, making proper payments, my licence was blacklisted and I have not been able to access the product for about a month.
The support system is just rubbish when it comes to providing after sales support. If the product is being sold in Germany, then there should also be a customer support helpline for such issues. All we can find is a support page that leads to a forum.
Further, this lack of responsibility from the company has costed me credits in my university for which i bought this product. I had an important project submission which was solely affected by this issue. And it has costed me my mental peace as well as my progress in my degree.

Either this issue be resolved as soon as possible else I will be forced to file complaint to authorities. If we customers stand by our commitment to pay our amount in time as committed, we too demand that the commitment is fulfilled on the other side.

ps- I have only attached a statement for the bank, but not disclosing transactions ids in the forum. If asked for, i shall share the transaction details in private emails of support personnel.