Here's the problem: Merkel can't politically justify to give Greece more german taxpayer money because it isn't spent wisely. After 5 years of crisis, Greece still has a primary deficit, while maintaining more extensive welfare programs than most EU Members. Even in the case of debt forgiveness, they would still have a massive household deficit and be in the same situation again soon.
So it's not about getting money back, it's about not burning more money.
So it's not about getting money back, it's about not burning more money.