Turkcell Charged Me More for the Same Plan Offered Cheaper a Month Later

Turkcell offered a campaign last month. My line was with Vodafone, and my contract had expired. I switched to Turkcell's Gold Festival campaign, which included 60 GB of data, 1000 minutes, and 250 SMS for ₺490 per month with a 12-month commitment. However, in December, they launched a new campaign called the Great Festival with the same content for ₺390 per month. When I called customer service to ask about this, they said, "That was last month’s campaign." I asked if anything had changed within the plan, like less data or fewer minutes, and they said, "No." They tried to explain something about competition regulations, but it didn’t make sense. I felt regret from the very first month due to the unfair pricing.