Turkish Airlines Miles Program Misleading Experience

I had a frustrating experience with the Turkish Airlines miles program. I wanted to use my 6500 miles before they expired by purchasing a ticket. The program made me buy an additional 10200 miles, and I ended up spending 49800 miles. In total, I used 60000 miles and paid ₺9200 in taxes. However, if I had bought 2 tickets with 40000 miles and ₺6000 in taxes, and purchased a child's ticket with money, I would have spent ₺13000. They charged me ₺9800 for the 10200 miles I was short. So, instead of getting 3 tickets for 40000 miles and ₺19000, I got them for 60000 miles (including 10200 miles for ₺9800) and ₺9200 in taxes, totaling ₺19000. In trying to save my 6500 miles, they made me buy 9000 miles unnecessarily and charged me the same amount. I am requesting a refund for my 9000 miles.