Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
if you purchase a subscription through the google play store , the sale is final and we will not provide a refund . 

```
. OPTIONS: ['Unilateral termination' 'Choice of law' 'Limitation of liability'
 'Jurisdiction' 'None' 'Content removal' 'Contract by using' 'Arbitration'
 'Unilateral change'].