I want a normal service with a decent connection, nothing more. That's what I pay for. Simple.
I don't care what they do with the money they get. They make stupidly high fortunes in a few seconds that many people would never see in a lifetime. They can quite easily afford decent services to provide and they are clearly NOT doing this.
How is complaining about not getting what I paid for being stubborn? Especially when they CAN fix it and refuse to?
Because the problem may not actually be fixable without upgrading to an Infinity type service. You don't appear to have said what the problem is but if it is rubbish speeds due to long line length then the solution really is to upgrade to something like Infinity. BT cannot change the laws of physics.
Again, if I'm correct (and if Infinity is available where you are), you're really causing problems for yourself by refusing to upgrade to a service that would presumably fix the problem.