About 1,700 heating oil customers whose orders were cancelled during a price surge are set to receive compensation after an investigation by the Competition and Markets Authority (CMA).

The watchdog said customers had complained that suppliers cancelled existing orders and offered replacement deliveries at much higher prices. The cancellations may have breached contracts. Customers received refunds, but many then had to pay more or go without fuel. Heating oil prices rose by 92% to 123p a litre at their April peak amid the Middle East conflict.

Some suppliers have agreed to compensate affected customers. Those who paid more for replacement oil will receive the difference, which the CMA estimated at between £150 and £350 for some people. Customers who did not buy replacement oil will have their original orders fulfilled at the agreed price.

The CMA remains in talks with suppliers that have not agreed to compensate customers and says it is prepared to seek court enforcement. It has also recommended new regulation for the heating oil market, including a supplier register and minimum standards for handling cancellations.