Mobile phone operator Three has doubled the cost of some of its monthly tariffs, to the anger of its customers.
It has sent letters to some of its oldest customers who are on so-called legacy tariffs, including the £15 All You Can Eat plan, telling them they are being moved to an existing deal costing £30.
Customers have 30 days to choose another plan or cancel the contract before they are switched on to the new deal automatically.
The move will affect hundreds of thousands of Three’s 8.8 million users.
Customers took to Twitter and used the company’s #makeitright marketing slogan to air their frustration.
“#MakeItRight @ThreeUK @ThreeUKSupport ripping off loyal customers,” said one social media user.
“@ThreeUK phasing out my contract and offering less for more? Way to treat a loyal customer Three! #Makeitright live up to your hash tag!!” said another.
The Hutchison Whampoa-owned company is hoping to take over rival mobile carrier O2 later this year, but the deal has been met with controversy due to fears that it will decrease competition in the market and lead to increased prices.
A Three spokesman said: “In March 2014, we introduced new price plans giving customers more options in the size of their data and voice bundles, as well as limits and alerts to prevent bill shock.
“We have a lot of tariffs that we no longer sell and moving customers to one of the new plans will ensure they can enjoy the benefits of these plans.”