Poland is a developING country
This is completely untrue.
Poland is smartly using its resources to MODERNIZE its infrastructure. All intelligently governed nations do this. A modernizing economy doesn't make it a developing country.
Indeed, the World Bank defines a developing country "...one in which the majority lives on far less money-with far fewer basic public services-than the population in highly industrialized countries. Five million of the world's 6 billion people live in developing countries where incomes are usually under $2 per day and a significant portion of the population lives in extreme poverty (under $1.25 per day). "
It further refines this by characterizing developing countries as experiencing mass migrations from rural areas to poorly equipped cities; a largely uneducated population where hunger is common; and unsustainable government debt.
The World Bank further categorizes Poland as being in the group of "high income" countries.
Granted many will regard "high incomes" as being those earned by workers in finance, entertainment and technology sectors but globally this isn't the case.
Regarding EU budget transfers Poland has been a net recipient of money over the years and did receive €17.44 billion in EU funding in 2014 alone.
But that's not to say Poland isn't contributing anything back.
Also according to EU figures, "In 2014 POLAND contributed €3.52 billion to the EU budget and collected €572 million in customs and farm trade duties on the EU's behalf, of which it retained 25% as an administrative fee."
Poland also contributed €294.4 million towards the UK's €6.07 billion rebate.