how do i unblock the toilet?

Try a drain cup rubber plunger. If it makes no attempt to go check the manhole it goes in to if clear then back to toilet keep plunging and boiling hot water and costic soada keep soda off your hands if wet it burns. If the manhole is full check the next one along to see if that is clear if so the blockage is in the between the first and second manholes. drain rods can clear it but may need specialist drain clearer.
I've had a manhole block and it's bank right up into the toilet pan.

Nobby
November 2008