Hai there, @Carl Langford
Well first of all, the High Power Cargo Pack was not intended to be used in MultiPlayer as TruckersMP themselves have not made this DLC but more SCS Software.
Meaning your argument of wanting your money back is useless as you did pay for the DLC indeed, however, its actual intention was to be used in Single Player which you can still do at any time given.
TruckersMP is not in charge of whether you buy a DLC or not.
Secondly, the "glitch" you have stated above isn't only the case with High Power Cargo Pack jobs, but also other jobs that you m