The very last pasuk in Eicha says "כִּי אִם-מָאֹס מְאַסְתָּנוּ, קָצַפְתָּ עָלֵינוּ עַד-מְאֹד.". The translation from the Atrscroll reads something like "For even if you had rejected us, you have been exceedingly wrathful against us". (The translation might be slightly different, as this is from memory). I was reading through this a few days ago, and it struck me - I thought that G-d could never 'reject' the Jewish nation. So how could it be that even in theory G-d could have possibly rejected us? If the author wanted to convey the idea that G-d seems to have left us to our own devices, surely he could have used a different language?
the previous verse reads: "Restore us to You, O Lord, that we may be restored! Renew our days as of old." Perhaps the prophet means to plea for the latter verse due to the harsh treatment received during the churban (destruction). Like a son who was beaten harshly by his father and the father feels bad, so the son seizes the opportunity to make a demand