Pegasus Airlines Disappointing Experience from London to Istanbul

I had the unfortunate experience of flying with Pegasus Airlines from London to Istanbul for the first time, and it was truly disappointing. Not another time! Unsatisfactory service! All they care about is making money, regardless of anything else. They went ahead and added an extra charge for my compact waist bag. Incredible. When I raised my concerns, the staff promptly changed their position. What type of service is this? No comfort whatsoever, and they have the audacity to charge for every little thing.