When a door-to-door contract is cancelled (other than by cooling-off) the seller may not claim, even under a liquidated damages or penalty clause, more than the statutory amounts plus statutory-rate late interest: the ordinary usage fee (or the loss in value) when goods are returned, the sale price when not returned, the price of services already provided, or the ordinary costs of concluding and performing the contract when cancellation precedes delivery; on non-payment, no more than the unpaid price plus interest.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.