Turkish Airlines Adana-Istanbul Flight Excessive Baggage Fee Issue

I had a bad experience with an airline company. I bought a ticket for my mother for the Adana-Istanbul flight and checked in online. All I had to do was drop off the luggage. A Turkish Airlines employee asked me for ₺2450 (approximately $88) to check in the bags. Wondering why? Because they have a rule that the credit card holder who purchased the ticket and the passport must be present at the baggage drop-off. I saw that the second ticket (also $88) was mentioned somewhere during the online check-in. I wonder whose pocket this money is going into. Was the seat the same as the first ticket? The employee said a new ticket needed to be purchased. Does it really cost $88 to check in luggage? My mother is traveling abroad, and Turkish Airlines wants me to provide my own card and passport.