BT should be structured on same level basis as the other public utilities: strictly wholesale/retail
When all the publicly owned utilities, gas, electric, water, fixed-line phone were privatised, I think the fixed-line phone utility and water, should have been structured on similar lines to gas & electric, where for each utility there was a strict separation of , the original monopoly supplier became a wholesaler of the underlying infrastructure only, and the consumer had a choice from several retail providers of each utility. With Gas & Electric, (although the original monopoly was also allowed to offer a retail service) the customer is no longer forced to deal with the now monoploy wholesaler, and thus benefits from freer retail competition unfettered by monopoly.
That is not to say supply of the Gas & Electric utilities is a totally competitive market: In run up to privatisation the goverment promised strong regulation to prevent private utility prividers exploiting customers. But as is reported, the cartel of 6 colluded to defraud the public in favour of themselves and their shareholders.
However, for reasons not apparent, the government chose not to sell Water & fixed-line phone with the same wholesale/retail protections. Water remains a privatised monopoly where the regulator does not prevent regional suppliers from abusing their monopoly power; eg Southern Water demand a prohibitive fee for 'disconnecting' unoccupied premises, yet adjacent Portsmouth Water charge nothing, provided the customer uses that service no more than 2 times PA.
In case of the original fixed-line phone monopoly, unlike with gas & electric, the government gave BT an unfair advantage over 'other' retail providers. A clear advantage given to BT was no matter which retailer the customer chooses, unlike with gas & electric where you deal only with the retailer, with phone you still have to deal with BT for provision of the line, and thus subject to BT's T&C in addition to the retailers. Although many retailers do not require a minimum of a 1 year contract, the BT 'wholesaler' does, so overiding the retailers T&C. BT have consistently abused this advantage the government gave them; eg. as reported in this journal a few years ago, BT 'wholesale' made use of the address list of all fixed-line phones in attempt to poach customers from 'other' fixed-line retailers, where the 'other' retailers had no access to their competitors addresses. A further example was the 'phnom' wire-tapping of 'BT' lines to sell on customers data to marketing companies. The press have reported many more abuses by BT of their still effective monopoly still leveraging their position over 'other' retailers, yet the government refuses to stamp out this abuse by putting BT on the same basis as wholesalers of the other utilities. Having to deal with 2 companies for 1 utility is onerous.
Monopoly power is a notorious breeder of corruption. Unless the government puts the remaining utility monopolies BT and Water on the same wholesaler/retailer basis as Gas and Electric where the public contracts only with a wide choice of retail providers, the monopolists will continue to abuse their power as shown throughout history.