FlixBus Cancels Tickets With Deduction And Coupons

I purchased a Barcelona to Paris ticket from Flixbus for October 12, but within a few hours, I realized that I had bought the wrong ticket and wanted to cancel it. Of the approximately 3300 TL I paid, around 800 TL was deducted as a cancellation fee, and the remaining amount was issued as a coupon to be used within one year. This is the first time I've encountered such a ridiculous policy. I actually reviewed the cancellation conditions before purchasing the ticket, but nowhere did it state that the refund would be given in the form of a coupon. Where am I supposed to use that coupon? Moreover, Flixbus justifies this with a ridiculous excuse like "the rules of the country where you bought the ticket apply." We all know that canceling a bus ticket in France or Spain doesn't cost this much. I've never come across such a practice with any other company. I demand a full refund of my money.