Something fishy in this tale.
At the time Big BT bought Plusnet, part of their justification for doing so was that Plusnet ran the business on a CRM package called WorkPlace. See e.g.
Other folks at the time (2006) wondered whether the purchase of Plusnet was less about WorkPlace, more about allowing Big BT to drive coach and horses through Ofcon's rules about BT not abusing their market dominance (e.g. by BT Retail not being allowed to significantly undercut the competition).