I assure you they are UK based, i should know the past few days i spoke to 5 different departments and about 7 different people lol... (did have slight issues but they were solved today

)
Depending on the option you choose on the phone i THINK/GUESS from my experience you go through to a 1 of 2 different call centres.
The sales one i would say at a guess from the voices is South east england.
The support option id guess is western england.
The accent you experienced may of just been a guy with a strong devon'ish accent or similar accent.
Either way i assure you their call centres are magic carpet, snake charming and elephant free
They definately are NOT based in India.