I constantly have 100.6 million diamonds in my game, never goes down. I've had this method working for the past 3 months and it still works perfectly. They don't check games installed from Play Store.yet. Install then via Play Store and the mod will still be on for unlimited diamonds etc and you can play the online events and upgrade everything without stressing out that Gameloft will ban you. Make sure you sign into a fresh Facebook account, create one if necessary and then as soon as you get signed in, leave the game completely and delete the mod. That will get you playing online for a few games. Your best bet is to find a mod with only unlimited diamonds and gold with no VIP 10 in as Gameloft has detected how that works now and it's instant ban for every modded APK for VIP mod. I've even amended the file after I pass the initial network access request and it still doesn't work! Gameloft have been very sneaky because even if you can get the mod to work, they have put the age to 23210 and there is no way you can input more than 2 numbers for age! I even amended the data file but as soon as Gameloft requests access to network, it overwrites the file to put that number in again.
BetaTestedUrGf, I have 1 phone that is rooted and was able to access the data folders for Gangstar Vegas.