Vodafone has been accused of misselling to customers.
Several customers have complained on website MoneySavingExpert that they did not receive the benefits outlined by Vodafone when they signed up.
Customers claimed they were not receiving the bundle allowances they had signed up for via telesales officers in the first place, or were being overcharged for their airtime.
A Vodafone spokesperson said: “Vodafone makes thousands of calls everyday and the majority of these are successful calls made to happy customers who get exceptional service and value from Vodafone. However, on rare occasions misunderstandings can happen.
“The majority of our calls are recorded and we use these recordings to help resolve complaints. We try to identify who made the call so we can make sure it doesn’t happen again.”