Hi Monster.
It's a shame that it's not working out, and I'm sorry for your loss.
Did any of the people on FB specify what you are doing wrong? If not then it's of little help when people say something is wrong but will not say what to do to make things right.... !
Do you mind me asking for more details as these things can make a difference.
1) How old are your guinea pigs.
2) What was your method of introduction?
Please take a look at these links:
Introducing And Re-introducing Guinea Pigs
Dominance Behaviours In Guinea Pigs
As general rules adults will often take readily to a youngster. If both the pigs are adults or in their hormonal 'teenage' years there can be clashes in personality. If both your sows want to be dominant it may not work out. Sadly as they have drawn blood they may have fallen out permanently.
When you introduce guinea pigs it's best done in an area that neither pig is familiar with, that way they are less likely to feel that the other is invading their territory. Done this way each guinea pig will take to the other, or not, based on personality. Often sows will work things out and settle together once each has established where they stand in the relationship, and it's easier for them to do this when neither has staken a claim on the area they are in. Sometimes though, even with sows, things don't work out.
If you take a look through and feel you may have approached this in the wrong way please don't feel judged, we'll try to advise you on where to go next x