Turkcell GNC 10 GB + 10 GB Package Misleading Info And Fee

I recently transferred my line to Turkcell from the Pendik Esenyalı branch. During the application, I repeatedly asked the staff whether both 10 GB and the extra 10 GB in the GNC 10 GB + 10 GB package could be used for social media, and I was clearly told that both would be usable on social media. Trusting this information, I accepted the package. Afterwards, I realized that the internet was not usable in the way it was explained and, since I was left without usable internet, I had to change my tariff to a 20 GB package. Despite this, Turkcell’s internet generally has very poor reception for me, it often does not work properly and sometimes even calls do not come through. In other words, I am already paying for a service that does not work properly. Today I received an SMS stating that a cancellation fee of approximately ₺400 is being charged. I have not been able to reach customer service and therefore could not explain the situation to anyone. I do not accept being charged a cancellation penalty for a tariff that I was misinformed about and that does not work properly in terms of reception and internet. I request that my tariff be cancelled without any penalty and that the cancellation fee reflected to me be completely cancelled, as I was misinformed at the Pendik Esenyalı branch and I cannot benefit from the service as promised.