Maybe that's why they make a separate install and activation charges for 50Mbps. Even though there is an offer running currently of free install on upgrades to 50Mbps they still charge that mysterious £20 activation. Lord only knows what it pays for - possibly a VM engineering dancing naked around your street cabinet at midnight muttering mystical incantations but more likely a 12 year old in Mumbai whacking something into a keyboard. Alternately it could be for nothing at all and just funds brandy and cigars at the end of board meetings.
If you can't fix it with a hammer you've got an electrical problem.