Can being the operative word.
I can name you multiple instances where it didn't work for me.
I keep my C level escalations for extreme scenarios, i.e. situations where BT have evidently f'd up really, really, badly.... for example.... taking a customer offline through sheer incompetence because someone who doesn't deserve to be called an engineer working at the local exchange decided they wouldn't bother checking whether an existing circuit was in use before re-using the capacity for someone else.
Trying to escalate through normal "customer service" channels proved tedious and frustrating as always..... a C-level missive yielded nothing..... the customer had to invoke their DR plan and their main office was offline for ten days before I managed to eventually track down some middle-management type at BT who felt like being remotely helpful in escalating the fix.
And you wonder why I always advise that people avoid contracting BT for services if they can possibly help it.
As far as I'm aware BT eventually took the work back in-house
Nope, they're still subbing... infact they're subbing increasingly more these days ! Hence the QoS keeps going further down the pan. I regularly see subbed engineers turn up who don't know what they're there for .... they ask me to brief them because all they've been given is an address and a contact name.
BT are increasingly subbing out because they contract their subs on an "on-completion" basis... this means that if a sub goes to a job but is unable to mark it as complete due to whatever reason (such as BT not sending out the correctly skilled contractor), then they have to return the job to the pool and the subcontractor does not get paid. This means that on some days the subcontractor can drive around town going to X jobs but only gets paid for 1 or 2 because they've been unable to complete the others..... which means they'v basically spent the day at a loss, hardly even paying for petrol. From the subcontractors I've spoken to, they obviously, desperately, want to complete all the jobs.... they don't like leaving jobs incomplete.... but if BT don't give them the details they need, then they're stuffed.