Mobile phone customers are being caught out by data usage limits - and facing hefty bills as a result, claims the Communications Ombudsman.
In its latest report, the Communications Ombudsman says it has seen an increase in the number of customers complaining about data services since mobile phone providers have stopped offering free data usage.
Andrew Bradley, spokesperson for the Ombudsman, says: "Customers come to us and say they haven't been given enough information by their mobile phone provider about the data usage charges.
"And while consumers should be aware of what they are paying for it's the phone companies' responsibility to make this information as clear as possible. If something says 'unlimited' it should be unlimited," says Bradley.
He adds: "The complexity of smartphones means that some consumers are not even aware that they are downloading large volumes of data, and find out only when the charges are spotted by the provider, or in some cases not until they get the bill."
Phone companies respond
Mobile phone companies have responded strongly to the Ombudsman's claims.
Vodafone says it doesn't use the term "unlimited data at all" and notifies customers by text if they are close to their usage limits.
O2 says it abandoned the term 'unlimited' a year ago and now only offers data bolt-ons.
"Once a customer is close to going over the usage limit on their bolt-on, O2 will send a text to warn them. They can then choose to pay for more data or once usage is reached they won't be able to download or use the internet other than to browse," says O2 spokesperson Andrew Cocks.
T-Mobile takes a similar stance. It's fair use policy for internet usage promises customers they will never pay more than their fixed monthly cost. If they go over their limit they won't be able to download anymore, but they can still browse online and check emails.
However, the Communications Ombudsman doesn't think providers are doing enough.
"While service providers do generally say that they will notify consumers when they are getting near their limits, alerts are sometimes missed, especially if they are sent by text to a stolen phone," the Ombudsman report warns.
Three is the only mobile phone network to still offer unlimited data packages, with its 'all-you-can-eat' data packages.
If you feel your bill is unreasonably high due to a lack of - or misleading - information you should contact the Communications Ombudsman via its helpline 0330 440 1624 or go to ombudsman-services.org to submit the relevant form.