@Paul ******
You will not be approved by the embassy for a 60 day visa without a proof of onward travel in 60 days.
But today almost nobody buys a 60 day visa anymore because visa exempt is also 60 days.
So you did apply for a 60 day visa with a 70 day flight, embassy granted and despite your visa airline did not accept?
I don't believe, but anyhow with a visa it is embassy who checks and not business of any airline, so your bolocks is bullsh1t.