I show that your account is currently using just over 100mb of disk space, this means you do not meet the requirements to get a disk space upgrade at this time. The requirement is usage of at least 75%, stored backups and usage inside trash would not be counted into this, so if you would have any usage of that kind it would need to be removed before a request can be made.
Note that you would not get unlimited, but you would get an increase of allotted space, which can be requested as many times as needed. The account will be reviewd for usage and compliance with ToS each time you do request an increase.
