EE has admitted its customer service for fixed broadband subscribers is "not good enough" and has committed to a major overhaul.
The UK operator was fined £1 million by the country’s regulator in July for failing to comply with its rules on handling customer complaints.
A month earlier, Ofcom revealed EE had generated the most complaints of all the UK’s providers for its broadband services.
It said problems relating to faults, service and provision (37 percent), billing, pricing and charges (20 percent) and complaints handling (20 percent) were the main drivers of the complaints.
EE has come up with a five-point plan to address its poor performance, which it said generated a "continued and unacceptable high volume of complaints".
It is opening a Broadband Operations Hub and hiring 500 new permanent customer service staff.
It said systems and processes across mobile and broadband would be integrated and aligned to boost service levels for all customers.
Finally, new digital and social media service tools plus a dedicated broadband customer hotline will be introduced.
EE said it would proactively contact its broadband customers to outline the steps it is taking.
Francoise Clemes, Chief Customer Service Officer at EE said: “Our Broadband Service...continues to fall short of what our customers expect and deserve – but I want to reassure them we’re addressing this as a priority.
“As well as opening a Broadband Operations Hub and bringing in a new team, crucially we are introducing integrated systems so that we can align processes between mobile and broadband.
“I’m not going to offer any excuses because broadband customer service has simply not been good enough. I promise all of our customers that Service is our top priority and, through Broadband Service First, we will fix this.”