The same exact thing happened to me a few days ago. I had to restore my Windows 10 installation, but then I found that my whole asphalt profile was reset to 0 on their servers. I wrote to customer support, but in the meantime, I checked another computer that I had played on and it still had my statistics in the local profile, even though it didn't have my most recent progress. When I opened that one up, I got a message saying "the local profile does not correpond with the server profile, which do you want to use?", on the left hand side I had local profile with all my progress and on the right hand side I had server profile with 0 progress. Which do you think I chose lol. The local profile on that computer was then synchronized to the server. When I went back to the first computer and opened Asphalt, it now asked me the same thing: "your local profile does not correspond with your server profile, which do you want to use?". On the left was local profile with 0 progress, and on the right was server profile with the progress as it was synched from the second computer. Of course this time I chose server profile.
So I guess if you don't want to risk losing your progress, a good way to back up is play on a different computer every once in a while, so your profile will be saved somewhere else locally.