Hi, We offer 24x7 support but unless you have enhanced care you are still only going to get basic support, this means you can log a fault, tests can be run and if its a robot fix then that will get passed to be done, stuck sessions and stuff like that are also done 24x7 but if the fault is in say the exchange with a line card for example then regardless of the ISP you are with (including BT Retail) this fault is going in a queue to get dealt with the following working day regardless on who you are with.
Again the only exception to this is if you have enhanced care but that's a whole different story.