Telecoms regulator Ofcom has fined mobile phone network EE £1mln for customer complaint failings.
The Orange and Deutsche Telekom owned group mobile group, which is in the process of being sold to BT (LON:BT.A) for £12.5bn, breached the complaint rules over a three year period between 2011 and 2014.
EE, which was trading at 4GEE, Orange and T-Mobile ay the time, did not provide the details of a dispute resolution system to some customers, said Ofcom.
'Deadlock letters' weren’t sent in some cases while in others EE told complainants that letters of this type were not issued.
Claudio Pollack, Ofcom's consumer and content group director, said: "It's vital that customers can access all the information they need when they're pursuing a complaint.
"Ofcom imposes strict rules on how providers must handle complaints and treats any breach of these rules very seriously. “
The fine reflected EE’s serious failings and the extended period during which they occurred, she added.