@saothienhat Sorry to hear that but let's not panic just yet as there are a few of ways the PVZ2 account might be recovered and let us go through the easier ones first.
1) Have you registered your email with EA to get 100 free gems? If you have then it might be possible to recover your old account by register again using the same email address.
2) Did you make note or take a screenshot of your old player ID? If so, your account data might still be intact on the server, your will need to open a new missing content case with EA HELP CENTER
3) In case the worst has happened and your player data was corrupted at the server end, have you got the game installed on more than 1 device? If so, go to the other device and TURN OFF WiFi and Internet data, then start the game and see if your original progress (plants/coins/gems/mints and gauntlets) still present, if it is, please make a note of your player ID, contact EA HELP and seek for further assistance.
IF you have not registered your email address and do not know the original player ID and you only have this game installed on one device, then you can start panic.