Hi, welcome to Just answer, my name is Ross, i will help with your question.
awaiting your answer
What type of bleeder did you use? Is this a high pressure bleeder that pushes pressurised fluid into the reservoir
Ok, did you depress the pedal at all during or before the bleeding process?
Ok, have you pumped the pedal and tried to re bleed it after pumping?
Ok, sorry for all the questions. Assuming there is no leaks or anything obvious like that, you need to try using a vacuum bleeder as i often have these problems with pressure bleeders, there will be air trapped in their somewhere if the pedal is spongy, getting it out can be difficult, a vac bleeder seems to get the air bubbles to come down and out of where they are stuck rather than letting the fluid flow past them. If there is no luck with this, there is really only one option left which will be the master cylinder seals, when pressure or vac bleeding, the pressure can push the seals backwards, the rubber seal flips over and doesn't seal properly letting a the fluid flow past the seals.
in what order should the brakes be bled
Ultimately it makes very little difference providing you push enough fluid through but to do it the quickest way using the least amount of fluid it should be started with the furthest from the master cylinder. It varies depending on the make and model but its usually 1 N/S/R 2 O/S/R3 N/S/F4 O/S/FDouble check by looking at the route of the brake pipes, one at the rear will cross from one side to the other, this is the first to be bled.