Outrageous Vodafone Bill

I switched to Vodafone in October, thinking I was signing up for a low-cost 81 tl -per-month plan. To my surprise, they sprang a massive bill of 255 tl, including taxes, just a month before my billing cycle ended if I wanted to continue with the same plan. I was barely scraping by with 81 tl! They now want three times my usual bill, and they want 500 tl or even 600 tl to switch to a different plan. It's ridiculous, and it appears that they've gone insane. If Vodafone's upper management can offer me a reasonable price to keep my current plan, I'd consider it. If not, I'll be switching to another provider the moment my billing cycle ends. Seriously, choosing Vodafone has been a mistake.