Shoppers paid £2.50 to be connected to Apple, Boots and H&M helplines which they could have called directly due to “misleading” ads, a regulator found.
The Phone-paid Services Authority warned consumers to be “careful and vigilant” when searching for customer service contact numbers online to avoid accidentally calling a premium-rate connection service.
The warning comes after it handed out a £250,000 fine to Plus que PRO SAS, which ran a website listing customer service helplines for a range of major companies.
Callers were connected to the firms via a connection service and charged £2.50 per call.
A tribunal found that the firm's website failed to tell customers that the numbers could be available for free or a lower cost elsewhere and it was not made clear that shoppers were not calling the firms directly.
The PSA also said it appeared that not all calls were successfully connected but that callers were still charged. Of roughly 1,900 calls the regulator monitored around 500 were less than 10 seconds long.
The firm had run promoted ads on search engines like Google and Bing.
Customers who paid the firm could now be eligible for a refund.
Jo Prowse, the chief executive of the PSA, said it was “totally unacceptable” that the firm had “misled consumers”. She added: “We have a strong record of enforcement against call-connection companies and have recently tightened up our rules in this area – we’re ready to take swift and firm action against companies who break these rules.” An attempt was made to contact the firm for comment.