Another Brake issue after replacement

[SLX5]

I replaced my brake pads and got the rotors resurfaced. I have done this many times before, but has never experienced this before.

Even at low speeds 10 to 20mph, the car shakes violently when I press the brake pedal. What worse is the brake pedal moves back and forth about quarter of an in at these speeds.Took everything apart and put it back together, the issue continues.

I have changed brakes several times including the X5's but has never experienced something like this before. When I decided to change the pads and rotors resurfaced, I didn't have any issues at all. Worked perfectly prior to to change,........Please help