Frankly I am amazed that anyone would put up with this for so long.
I live a few miles to the North, although on a different exchange, Horndean,.
Many in this vicinity have walked away from TalkTalk, and all one needs to do is look here:-
to understand why.
It might be worth migrating to Andrews & Arnold, who can virtually assure a great experience. They are not inexpensive, but offer great value for money.
Their Home 1 package, specifically aimed at home users starts with ADSL and 300GB/month download for £25.00 per month.
If after a period of time with A&A your friend could migrate to someone less expensive, but in my experience very few people do.
Edited by NJSS (Thu 30-Apr-20 07:43:50)