Online flea market operator Mercari will improve its product confirmation process and expand the range of items for damage compensation, the company announced on Monday.

The company was criticized on social media for failing to adequately respond to sellers’ complaints that items different from those they sold had been returned by buyers.

Mercari will set up an item collection center to compare traded goods with explanations from sellers and buyers. It will also build an artificial intelligence system to detect fraud and strengthen reporting functions for inappropriate use of its services.

“We will achieve rapid solutions to difficult-to-resolve disputes between customers by better engaging with them,” a Mercari representative said.

In a social media post, an online flea market seller said the buyer of one item had returned a different item and that Mercari’s response to the seller’s complaint was not appropriate. The message was broadcast later.