Hi, this is a very common issue with a very simple fix. All you need to do is go to:
My documents --> Euro Truck Simulator 2 --> Profiles --> (whatever the next folder is. e.g '42656E6E79303830383938') --> Then open the 'config' folder in notepad, and find ''uset g_force_economy_reset "0".'' and set the value to ''1'' and save the file. And then restart the game!)
P.s: once you have gotten back in the game set the value of ''uset g_force_economy_reset "1",back to ''0'', (and don't forget to save file once your done), or else it will keep resetting the jobs every time you start up the game!
Simple as that! Hope it helps!
Happy Trucking!