Really, someone broke into your home, stole a rabbit and a guinea pig and left everything else untouched?
NOT.
If this is the case, you came home and those two animals were gone but everything else was unchanged, then this was an inside job, meaning someone you know and trust with access to your home went to you house when you weren’t home, entered and stole them.
To what end? I can’t imagine that they were valuable. By your own admission on your profile, the rabbit was a baby accident when you mistakenly let a male and female get at each other and the pig has a defect which made him un-sellable.
If they are not valuable and the friend was merely so in love with them that he/she stole them to have them constantly in his/her presence, then that person is a flaming idiot because eventually you would go to that person’s home and see your stolen pets, or evidence of this person suddenly owning a rabbit and a pig.
Are you absolutely positive they did not somehow escape on their own?
If you are sure they were stolen and there are no signs of forced entry and nothing else was taken, then I’m sorry but it’s obvious that someone you know did this to you.
Start looking at anyone with a key to your home.
Do you live alone, aside from your other pets? If not, look long and hard at your housemates. Someone may secretly hate living with a menagerie and reduced the number by two, going for the most helpless animals first.
If you still live with your parents, I hate to be the one to suggest this but they may have gotten sick of having a lot of pets and dumped those two behind your back.
Even if no one stole them and they somehow managed to get out on their own, they are unequipped to live in the wild and would not last long.
This is terrible, but I truly fear you have seen the last of those two.