Is there someone from Spark with some authority that can help? To summarize - 

My folks live in a semi-rural area and the broadband speed has never been faster than 1-2 Mbps.
They've put up with this, but at least the connection has been semi-reliable. Now though, it isn't. 
Now it drops out all the time and is basically unusable. It wasn't working at all yesterday, with the upload speed being zero.

We're told by Spark that the exchange is too old and there's nothing can be done. It's "congestion". Chorus has no plans to upgrade it either.
We were phoned last year about getting wireless and said we would sign up, but after nothing happened were told it was actually unavailable.

Now I find that I can't even send an email. Just getting a message - "The connection to remote server shared.xm1.smxemail.com was refused or timed out while attempting to connect."

Am using my phone's hotspot at the moment to be able to use the internet at all 

Any help appreciated...