I am having issue with my google drive as well, they calculated the wrong storage usage and I simply cannot upload more files. I spent weeks to convince the support it is their bug that clearing cache is not solving the problem. They said they're going to follow up but nothing happened. I then just cancelled the plan, now gmail is complaining not enough space and will stop receiving email. I told the support my situation, and they gave me extra storage for a month while they're dealing with the problem. Though the problem is never resolved, and I now have to send an email to extend that extra storage every month.

Seems like a proper way to get support from big companies in 2017 is to post on hackernews.