You are not going to have this fixed without consulting support from Rockstar as there is nothing that can be done to fix this other than contacting Rockstar support there self. It is possible it could have been a glitch or bug of some sort. Usually when they have intentionally reset anything they notify you via a in game message and email with the associated psn and social club email linked to your account.

If you have ill legitimate in game money and rank then it's possible and probable that's why the account was reset if they even reset it to begin with. But assuming since you have not stated otherwise that you have not received any notification of any sort stating your account was reset. Then it sounds like it was a unfortunate glitch/bug/fluke/error you have experienced. Best of luck to ya my friend hope all get's sorted out.