The gas bills had a strange ability to grow of their own accord, almost seemingly to the whims of the natural gas supplier. On several occasions Russia cut off supply during winter after disputes, which affected not only Ukraine but Europe. This was a two pronged maneuver which was meant to sour Europe-Ukraine relations and keep Ukraine dependent on Russia. Ukraine's attempted aligment with Europe is perhaps the main driver of the 2014 invasion of Ukraine by Russia.
So you have no sources I presume? And the bills were not paid.