Transport for London - making life difficult for shopkeepers - AGAIN

Shoppers are being fined for parking for more than three minutes in loading bays that permit 20 minutes (according to the signs). However since the CCTV cameras have gone up hundreds of drivers have been hit with fines because they have been seen away from their vehicles for more than 3 minutes. This is happening locally to shops in Kensington High Street - Leyland - a local builders merchant is suffering because customers waiting to collect items, or have paint mixed are in the shop and not waiting by their cars and vans. The wine merchant on the other side of the street is also suffering. Do you know any other local shops that are affected? Can we influence on Transport for London to keep to the 20 minutes on the sign for loading, and not penalise drivers after 3 minutes. When you challenge TfL on this policy, they say it is just up to the customers to explain why they received the fine. What's your experience with TfL?