Gotogate Refund Voucher Balance Invalid After 90% Refund

I purchased an airline ticket through Gotogate and additionally paid for the “refundable ticket” service. During the purchase process and in the confirmation emails sent to me, it was clearly stated that 90% of the ticket price would be refunded in case of cancellation, and based on this information I completed my purchase. Due to visa-related reasons, I cancelled the ticket under Booking No: 11.2-5.6-..0 on 28.01.2026, and on the same date a refund voucher in the amount of ₺9,229.00 (Voucher No: MT.NXU.R..) was issued to me. Later, I used this voucher to purchase a new ticket for ₺6,486.00, leaving a remaining balance of ₺2,743.00 (approximately €53 at an exchange rate of ₺52). When I attempted to use this remaining balance, I received a notification that the voucher was no longer valid. I then contacted Gotogate customer service, and I was told that I had already confirmed all conditions and that the voucher was single-use. However, this limitation was not clearly and prominently presented during the purchase process, it was not explicitly stated alongside the 90% refund information, and it was not separately communicated in the voucher email. The way it is currently reflected does not appear as a simple 10% discount on the refund amount, and it is not transparent for the consumer. Limitations that directly affect the consumer’s economic decision must be clearly and explicitly disclosed prior to purchase. Including such a significant restriction only within general terms and conditions does not constitute sufficient and transparent disclosure, especially when the main promise to the consumer is presented as a “90% refundable ticket”. For these reasons, I request that the remaining voucher balance be reactivated for use or, alternatively, refunded to me. If this issue is not resolved, I will proceed with filing a formal complaint before the Consumer Arbitration Committee. I kindly request your prompt resolution of this matter.