To little/no avail
Definition 1 of 1
Pro Tip 1/3Effort Wasted
Indicates that someone's hard work or effort has failed to yield the desired results. 
She studied all night to little avail; the test was too difficult.
Pro Tip 2/3Persistence Fails
Suggests that even persistent efforts have not led to success. 
He negotiated relentlessly to save the deal, but to little avail.
Pro Tip 3/3Disappointment Implied
The phrase often conveys a sense of frustration or disappointment. 
They lobbied for the change to no avail, leaving them disappointed.