Constantly Slow Turkcell Home Internet Speeds

I'm fed up with Turkcell's home internet. I've been using it for 2 years, yet despite paying for 50 MB, I constantly get only 0.1 MB speed. I can't even load a single website without resetting the modem and power cycling it repeatedly. I can barely use it normally for 30 minutes to 1 hour. My contract expired, and when I called to renew and mentioned the issue, they assured me it wouldn't happen again and locked me into another year. They checked the infrastructure, sent a paid team to my home who found nothing, and left. But my internet still hasn't improved in any way; the same problem persists. It's a shame.