What you said in your question concerning
including the wrapping paper weight in the meat gross weight, and the big difference that occurs, as well as selling the goat's meat as sheep's meat and the like, are all forms of cheating and deception. This is forbidden in the revered Shari`ah, for Allah (Exalted be He) stated:
And eat up not one another’s property unjustly (in any illegal way e.g. stealing, robbing, deceiving, etc.)
The Prophet (peace be upon him) said:
"He who cheats us is not of us (is not my follower).''
(Part No. 13; Page No. 231)
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.