My brake pedal is soft

Well my brake problems seems like an endless one, leaving me clueless and researching nonstop. My brake pedals are soft when I press it and when I have to stop short I would have to press the pedal pretty much all the way down. Now the thing is I have brand new Acura OEM pedals, which I just recently got ripped off by the dealers doing and plus I must have had the Brake lines bled around 3 times in the past few months, one of the times was by the Acura dealer also. Now the problem is every time the lines are bled it becomes soft in like 2 weeks or so and so far the only thing I have replaced was the Master Brake Cylinder and also new pads along with resurfacing the rotors.

I've only been told by the mechanic I went to that maybe its my ABS modulator but thats a maybe, which is an expensive maybe if I tried it. I figured I post up my problem before I start getting ripped off even more going from one problem to another and being some what of a car noob all I can do is just research and try to understand and comprehend other pplz posts. So im stuck at square one and alittle ticked off I ve spent quite a decent amount of money and not getting anything fixed :(. Sorry for the long post by the way, its just that I cant give up trying to fix this problem because its on my mind all day long. I d be happy if anyone can sort of guide me into the right directions thanx.

P.S one of the symptons is this

- Pedal feels mushy a low speeds. Double pump tend sot help a little