A problem with Russian weapons on Cyprus

Washington Times:

The Greek Cypriot army is having bad luck with weapons purchased from Russia.
After a fiasco with costly Russian missiles that could not be deployed, the army has been forced to ground a fleet of Russian-made helicopter gunships because no spare parts have been delivered and its pilots cannot read the Russian-language instruction manuals.
Only one of 12 MI-35 heavy gunships purchased in 2001 is still operational and that is used only "when absolutely necessary," said an official who spoke on the condition of anonymity.
The other helicopters, meant to become a powerful deterrent against the Turkish tank force in the northern part of the divided island, are waiting in the hangars of a somnolent air base near Paphos.
Turkey maintains an expeditionary force of 35,000 troops in northern Cyprus, consisting of two infantry divisions and an armored division of more than 200 tanks.
The heavy Russian helicopters pack an arsenal of anti-tank rocket launchers, 30 mm guns and mine dispensers.
Russians like to call it "the flying tank." In July, one crashed, killing its Cypriot trainee pilot and his Russian instructor. Now 10 others are effectively grounded, waiting for spare parts and English- or Greek-language manuals.
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During the 1990s, Cyprus bought a sophisticated Russian S-300 air defense system intended to keep out Turkish planes, which had roamed the skies unopposed during the 1974 invasion.
Many Greek Cypriots considered the promised 48 ground-to-air missiles a miraculous weapon.
But delivery of the system, which cost the Greek Cypriots $227 million, was postponed several times, mainly because of Turkish threats of immediate armed intervention.
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So why do they keep buying weapons from the Russians? Isn't that the definition of insanity to expect different results from doing the same thing.