A more important point though is will another broadband provider be able to do any better?
At a guess you're on FTTC (up to 80Mbps) service, and the cause of the instability is very like to be a fault in the Openreach cabling to your home. So if you were to sign up to say Sky, or EE, on an up to 80Mbps service you would like get a similar service unless the fault is fixed.
If you have the option of Full Fibre via Openreach or another fibre company then ordering a full fibre based service should be a solution to your problems.
I have made a number of assumptions in what I have suggested above...
We need some more info to help further. What service did you have with TalkTalk, what was the problem, and what did TalkTalk do to try to fix it?