Frustratingly Slow Internet Speeds from Vodafone

I am experiencing extremely slow 4.5G internet speeds with Vodafone. This kind of sluggishness is unacceptable from a service provider. I have called them numerous times, conducted tests in different locations using various devices, and yet, when I contact customer service, they dismiss me with excuses like "Let us fix your internet settings" or "There might be an issue with your SIM card." I have tried everything, including changing my SIM card. I even tested it on my acquaintances' devices, and the performance was equally poor. One customer service representative even told me that in order for work to be done in my area, the internet speed needs to be below 2 Mbps. But how is it possible for a 4.5G internet to be slower than 2 Mbps? This has been the same for two years, whether in Istanbul's Arnavutkoy or in Hatay. I am currently in Konya Selçuklu, and the speed is still incredibly slow, not even reaching 2 Mbps, sometimes dropping to kilobytes. I can't even perform accurate measurements at times. It's time for you to fix this, or else I might have to switch providers. I am tired of this. The pricing may be good, but what good is it when I can't even use the internet due to the slowness? If you claim to record our complaints, don't bother, it's useless. They open a case, but there's no action taken. They say they updated my settings, but it's all empty promises. If you're going to fix it, then fix it.