Nothing works

Ok so my Telstra app messaging doesn't work never has worked im getting pretty over Telstra you can't call you can't use the internet at night I think my average download speed is about 35 to 40kb/s but most nights I get a max speed of 10kb/s it's pretty annoying having to wait 5 minutes just for a Google search to load I'm just over Telstra you can't even call the local store because they don't answer their phones I live in a small town I spent 1 hour one day just trying to get through and what not one answer... This is a telecommunication business that can't even answer their own phone how do I get support to try and fix these issues I'm over it