Whitstable Exchange LLU very slow

My father has been on the LLU product for about six months, everything was fine until around 6 weeks ago and now speeds are very poor; at peak times the connection is totally unusable on just standard web browsing and email.

I was down there a few weeks ago and checked everything out his end, the SNR was around 15db downstream and higher upstream, and the connection very stable yet just standard web browsing was unusable. I've checked everything on his PC and that all seems ok, which is also bourne out of the fact that outside of peak times web browsing is ok.

The exchange is not on the list of exchanges to be upgraded and when I spoke to level 1 support a few weeks ago there were no known issues.

Basically the support call is going nowhere and we are getting very frustrated, the last action was to send him a new modem (which they charged him for despite saying there was no cost), and they have treated the issue as a customer-side problem when it clearly isn't.

I don't know if any talktalk people hang around on these forums but any help would be appreciated.

If you look on the service status page of the TT website, you will see that there have been unspecified issues affecting network performance over the entire network since 29 October which are not yet resolved. Judging by the way TT have dealt with previous problems, this will be resolved eventually. I have already noticed a difference in the last week. My exchange was not on the list before.