The money was lent to improve the Greek economy. It was largely spent on an unnecessarily large army, a large, inefficient and extremely well remunerated civil service, olympic games, cushy early retirement deals and shenanigans like that.
One thing that gained Syriza some centrist votes is that they come across as at least having clean hands: good or bad policies, people believe they aren't caught up in clientelist networks and stealing millions personally. Whereas the previous ND/Pasok unity government was widely suspected of still trying to cover up skeletons in its closet (e.g. the scandal over trying to suppress the Lagarde list didn't improve its image).