Openreach has stressed its commitment to offering the best possible service to its customers.
According to BT's infrastructure division, managing more than 20 million broadband connections is "not a simple task", ISPreview.co.uk reports.
However, Openreach said it "does get things right the vast majority of the time" and considers improving service its "number one priority".
"We are sorry where people have suffered or are still suffering service problems," a spokesperson commented.
Openreach stated that it offers service providers a range of repair levels that vary from six hours to three days, which allows them to decide the best options to offer their customers.
The organisation pointed out that about 80 per cent of its repairs are carried out within two days.
"If we miss an appointment or fail to fix a fault within the agreed timeframes, then we pay compensation to our service provider customers automatically," it said.
Openreach added that it has made "a lot of progress" with customer service over the past year.
Indeed, the spokesperson said it has been exceeding the targets set by Ofcom and is on course to halve the number of missed appointments it is responsible for to 2.5 per cent.
The comments came shortly after Citizens Advice called for the compensation system in the broadband market to be overhauled, as it is "deeply unfair" to consumers.
The body pointed out that Openreach typically compensates suppliers for each day that there is a delay fixing a landline fault or setting up a new landline or broadband connection.
However, Citizens Advice said customers who have been inconvenienced do not get anything to compensate for their losses and must "fight for a payout".
MPs have therefore been urged to support a clause in the Digital Economy Bill giving Ofcom the power to introduce automatic compensation for consumers.
According to figures from Citizens Advice, 20 per cent of repairs carried out by Openreach were not completed on time between April and September, along with six per cent of installations.
The organisation said this means an average of 14,000 households and small businesses waited longer than they should have for repairs to broadband and phone lines, while a further 11,000 experienced late installations.