if we lived in poland we would attempt your language ,if you want to live in the uk then speak frickin english .
Ever heard about thousands of Polish soldiers that stayed in the UK after the end of WWII? Did they not integrate? It's a rhetorical question, because we all know they did. They are still Polish communities spread all around the island that cherish their culture and origin, but generally they accepted the English way of life, and caused no further problems.
And they didn't had an easy life at the beginning. Just like today, they were also accused of taking the jobs, and under cutting the wages, but they stayed and now they are considered normal British citizens.
The same situation will happen with the current immigrants. Give them some time, just like you are giving it to the Pakistanis, although they did come to the UK later than the Poles, and after all those times, they still seem to cause some friction in the society.