Over the crowds of holiday shoppers in China's big stores this Spring Festival lingers an atmosphere of suspicion.

With charges of price deception hanging over the big chains of Carrefour and Wal-Mart and local authorities moving to levy fines, many Chinese -- normally averse to be pinching pennies during the Lunar New Year -- are checking their receipts at the tills.

The New Year, which falls on Feb. 3 this year, is normally a time of largesse and excess -- all the more reason why many shoppers feel so betrayed.

Customers can be seen recording label prices in notebooks or calculating their final bill on their mobile phones as they walk the aisles.

At outlets of Carrefour and Wal-Mart in cities such as Beijing, Shanghai and Chengdu, the check out queues have grown as customers double-check prices at the tills.

"I would never have imagined global firms would do this intentionally and I have to be cautious," said a woman surnamed Wang, after shopping at a foreign-owned supermarket in Chengdu, southwest China's Sichuan Province.

With three bulging shopping bags, Wang stood next to the check out to calculate the final bill: "We buy a lot for the New Year celebrations, so I have to be more careful."

The official weeklong Spring Festival holiday, which starts Wednesday, is China's closest equivalent to the West's Christmas shopping season, with generous gifts of food, tobacco, liquor and other presents for family and friends.

According to the Ministry of Commerce, China's retail sales hit 340 billion yuan (49.8 billion U.S. dollars) during the Spring Festival holiday week last year.

"The deceptive pricing practices of the two foreign-funded supermarket giants were a total scandal," said Wang. "I have to be careful with the prices and the labels."

"Cheating by the supermarkets is the same as stealing. I might have suffered losses as I don't normally check receipts," said a Chengdu man surnamed Li.

Wal-Mart (China) Investment Co., Ltd. offered a "sincere apology" to affected customers on Thursday. The company has been cooperating with investigations into the cheating. It has also launched inspections of stores nationwide.

Chen Bo, spokesperson for Carrefour China, said Sunday that Carrefour sincerely apologized to Chinese customers for inconvenience and losses caused by pricing irregularities.

Carrefour would refund customers five times the difference between the price charged and that on the label. The refund policy would be implemented at Carrefour's 182 outlets in China.

The issue is continuing to smolder on the Internet, with websites asking people to write in with "your experiences of price cheating by the Carrefour."

A survey by Sohu, one of China's major web portals, had resulted late Sunday in 8,451 of 9,507 respondents saying they "would not go to Carrefour as it is blacklisted for price cheating."

"Carrefour will further strengthen price label management and improve service quality to gain the support and confidence of Chinese customers," said Chen Bo.

Carrefour had drawn up short and long-term measures to solve the price label issue, including price inspections, improving and upgrading the price label system, and comprehensive staff training.

"We will have our special control group conduct frequent and wide-ranging internal price inspections," Chen said.

The National Development and Reform Commission (NDRC), China's top economic planner and price regulator, said Wednesday that some Carrefour and Wal-Mart stores in China were involved in deceptive pricing practices.

The NDRC ordered local pricing authorities to urge stores to correct their wrongdoing, and pay fines five times the illegal income. It also urged authorities to step up price checks ahead of the Spring Festival.