I agree, with some explanation so you lbrookep13 know what's behind all this.
Shoaling species of freshwater fish need a group of their own species to function normally. This is programmed into their DNA so we call it an inherent requirement. Without others of the species, they will be under stress; this can be handled in two ways, increased aggression or the opposite. Both are the only methods the fish has of dealing with the situation. The green citation in my signature block refers to this aspect.
There are several reasons why the group is important: security, interaction, hierarchy are the main issues. Different species may rely more on one or more of these, but they have that inherent need and without it they will not be in the best condition, or healthy as they could otherwise be. A scientific study a couple years ago documented for the first time that increased aggression was the normal response when there were insufficient numbers of the species.
Turning to the Tiger Barb species, we have a fish that is normally on the feisty/aggressive side. Excessive aggressive behaviour can be curtailed with more I the group, at least 10. This can only occur in a 30 gallon aquarium, minimum. And with no other fish species. Larger groups in larger tanks can have other species included, provided they are well thought out. Not every fish species will manage with any other, both ways.
We don't know how long these two barbs have been subjected to this frankly cruel behaviour,. but that is not your fault, it was done and now you must move forward as best you can. It might be inadvisable to put these two in a larger tank with more of their species; we cannot forsee the result unless we do it. Monitor their behaviour, give them the best care you can, and hope things work out for better not worse.