The price you accept at the beginning is not what you pay at the end!

It's a ***** taxi app. The price you accept at the beginning is not what you pay at the end. At first, the price for my trip was 150 czk(6 euro) then in 2 seconds it became 250 czk(10 euro).I was in a rush and accepted the price 250 czk but at the end of the trip I was charged 390 czk(almost 16 euro!!) from my card. The payment I noticed that the destination address wasn't my, it was more far away. I tried to contact customer support to explain to me why I was charged that higher price. I received a reply only on the 3rd day that "you are right that address is different and probably the driver forgot to cancel the trip and we will talk t him and here we offer you 2 discount codes for you next trips but you can use them together"! Nothing about why I was charged this money, nothing about refunding, only 2 codes that I can use only for 2 different trips to make me spend money again on their service, which I don't want!