BiTaksi First-Use Discount Cancelled After Cash Payment

I used a yellow taxi today in Ankara Çankaya via the BiTaksi application between 11:18 and 11:32 for my son. In the application, a first-use campaign of a ₺350 discount was clearly promised. In order for the payment to go through from the application and the discount to be applied, payment was tried many times through BiTaksi, but the transaction did not take place. In the end, the driver took the fare in cash from my son, and afterwards the promised ₺350 discount in the application was cancelled by BiTaksi. Because of this situation, both the campaign promise was not fulfilled and my son had to pay the full amount in cash. I request that the ₺350 discount be applied as promised, that any unjust charge arising from this situation be refunded if present, and that an explanation and apology be provided regarding why this problem occurred.