Busuu Started a Subscription Without My Permission

I would like to report a problem with a Busuu subscription that was accidentally activated through my Türk Telekom mobile line today. Even though I did not intentionally subscribe or knowingly authorize a membership, I received a text message from the 3699 service informing me that my Busuu subscription had been activated and that $7 had been charged to my mobile account. As soon as I noticed what had happened, I canceled the subscription the very same day.

Although I canceled the subscription on the day it was activated, I do not accept being charged for a service that I never intended to purchase or use. I immediately contacted Busuu by email about this issue, but I have not received any response.

I request a full refund of the $7 charged for this unwanted subscription. I also ask that the necessary measures be taken to prevent Busuu or similar mobile subscriptions from being activated on my phone line without my explicit authorization in the future.