Relation between multi-sig and single-sig addresses (in BCCAPI library)?
The call to receiver.getTypeSpecificBytes() strips off the version byte (the '3'), and ScriptOutputStandard() always creates a P2PKH script from this raw (with no version byte) 20-byte hash. The bitcoin that was sent to the P2PKH address is probably irretrievable.

You probably meant to do this to create a P2SH script:

val so = new com.bccapi.bitlib.model.ScriptOutputMultisig(receiver.getTypeSpecificBytes())


Also, just FYI I don't think BCCAPI is being supported any longer. I don't see any updates to it since late 2012, and the then maintainer has since moved on to create Mycelium. You may want to consider an alternative Java Bitcoin library such as bitcoinj.