Ki Teitzei 5777

In 25:13-16 the Torah tells us not to cheat in business. We shouldn't own different weights and measures to increase our own wealth as it is a form of thievery. The Gemara in Baba Basra (88b) discusses the severity of cheating in business to the point that it is harsher than the forbidden relationships mentioned in Leviticus 18. In both instances, the Torah calls "these actions" (in Hebrew "eleh") abominations. However, in Leviticus 18:27 "eleh" is spelled with one less letter; in our parsha, it is spelled out fully. The Gemara notes that a fuller spelling indicates a stronger language and therefore cheating business is harsher.
Why is this so? The Gemara concludes that one can do teshuvah if one sinned with forbidden relationships, but cannot when cheating in business. Rashi notes that when a person steals from the community, it is an impossible situation. When one steals, one is required to return the actual object to its rightful owner. However, it is very difficult to return the exact money to its rightful owner, let alone a whole community. While it possible for the thief to use those funds towards communal needs, it is not deemed a full teshuvah.