The consumer watchdog ACM has warned online shoppers not to buy underwear from a website claiming to be the official retailer for lingerie brand Sapph, following a deluge of complaints.

Customers who ordered underwear from shopsapph.com complained of late deliveries or products not arriving at all, while others who sent back their purchases and claimed a refund within 14 days said their payment was delayed.

ACM also said UltraCool, the company behind the website, had misled customers by claiming to be an official stockist for Sapph and had ignored repeated demands, including a court judgment, to stop misusing the brand.

“UltraCool is wrongly giving the impression that consumers are buying products from Sapph,” the ACM said in a statement.

The watchdog said it had held talks with UltraCool about changing its working practices, but without success. The company claimed that the problems were related to “older” orders and it was working on a solution.

The ACM said there was a “real and acute risk that more consumers will be disadvantaged” because it was still using the Sapph brand to sell products. “Therefore the ACM has decided to issue a public warning about this web shop.”