Petition Letting agents terms and conditions and renewal fees

The OFT's case against estate agents "Foxtons" and the judge's ruling failed to address the main cause of consumer complaints - renewals.
Should letting agents be entitled to open ended fees for the total duration of a residential tenancy?
Agents provide no service on renewals.
In London, agents operate a cartel and impose their terms. Consumer landlords cannot shop around. After the "Foxton's" case they use wording to get around the ruling to enable them to maintain open ended fees, sometimes trying to collect rent and their fees every month, sending the balance to the landlord. Or fixing contracts for say two to three years and claiming 20% or 30% of the rent over the whole duration of the tenancy which is unfair.
The Government must legislate. A law is needed limiting agents letting fees (separate to management and other charges agreed) to a percentage - usually 10% - of the first year's rent.