(ECNS) �C About three quarters of best-selling products had their prices hiked before a sale began during this year's "Singles' Day" (Nov. 11), China's top economic planner said in a report released on Tuesday.

The shopping frenzy saw transactions total 122.93 billion yuan ($18.95 billion), generating 678 million mails and packages, making the promotion campaign the largest in terms of scale since its debut in 2008.

While most of the 7.5 million products on sale at seven major e-commerce platforms neared their lowest prices in 2015, nearly 60 percent had their prices raised beforehand -- some of which had been found with a price hike of more than 200 percent -- and then lowered on "Double Eleven Day," the National Development and Reform Commission said.

Compared to price trends of the previous two months, 53.6 percent of the products put on sale on November 11 actually became more expensive, and only 34.6 percent saw substantial price cuts. In particular, 75.5 percent the best-selling products had experienced the "price hike first and then cut" scenario.

Electronic products, clothes/shoes/socks and home appliances took the top three places of dishonesty in e-commerce, accounting for 35.28 percent, 23.97 percent and 12.31 percent respectively, according to the report.

Among electronic products, cell phones (57.8 percent), tablets (19.48 percent) and laptops (12.08 percent) saw the most cases of dishonesty, mainly involving product quality, false promotion and price cheating.

In addition, cosmetics, food and drink, maternal and baby products, and household products all saw cases of dishonesty, accounting for more than 5 percent.

Customers were unsatisfied with after-sale services, and complaints about after-sale services in household products, building materials and electronic products remained high.

An analysis of 4.88 million online shoppers showed that most purchases in 2015 concentrated on lower-end products, and online shopping was more popular in economically developed provinces and cities than their less developed counterparts. Clothing/shoes/accessories/bags, sports and health products, and home appliances top the online expenditures, according to the report.