Brake pedal higher and brake creep after brake lines changed

[Nsr500rossi]

My 2.0 hdi has just had both front to rear brake lines changed 

Now my brake pedal braking point is a lot lower, it was a lot higher before

It also felt a lot more solid before and if I have the van running I can pump the pedal and the pressure builds and the pedal ( bite point is higher) like it was before, if I keep the pressure on the pedal it very slowly sinks

I have returned to the garage and they bless the brakes again but it seems the same 

I have just taken it back to the garage and they said there is no air in the system but they can make the pedal higher by adjusting the rear brakes 

What do you guys think is wrong

Thanks