In Kamyshin Megafon "shakes" clients "by default"?

"I want to tell how the popular mobile operator Megafon with pig-headed clients dexterously "finishes". I will give only concrete history which happened personally to me. I used a tariff which quite suited me: 2 gigabytes Internet and 400 minutes a month for 350 rubles with payment in the middle of the period. Several times lovely creatures with angelic voices imposed me various more expensive tariffs, dialing my number of the mobile. I politely refused...