Vodafone's Sneaky Price Hike, Unannounced Contract Changes

The second period of my Mega Vodafone 1 unlimited red plan was going to cost me 288 TL. My plan's first period cost 208 TL, and the price for the second period was set at 288 TL. However, Vodafone unilaterally changed the contract to 320 TL without prior notice or making the contract details visible within the app. If I continue with the second period without knowing, it shows an approved charge of 320 TL rather than the 288 TL that was agreed upon. If I remain a loyal customer for the next year and choose to keep my plan at 288 TL per month, I demand that any price increases that occur during that time be communicated to me. Vodafone should not make unauthorized changes to my contract without my prior consent.