No, a pelham bit is not approved at all: http://www.usef.org/documents/FormsP...entBooklet.pdf
Shows exactly what is allowed.
A double is allowed but this is 2 separate bits, the snaffle and curb bits are separate. A pelham where 1 bit has both a snaffle and curb action is NOT legal and you should have been penalised if not eliminated for it.
Still sounds like a back yard show, I've only ever known one show where I could have used a pelham and that was my school horse show where just about anything went, they hired in horses and you rode what you were given in whatever tack it came in (except for those with thier own horses). It was essentialy a back yard show, the aim was to have fun and everybody got a rosette. It was not competative (other then for the house points that were up for grabs)
Sorry but I do believe that you are a young kid with delusions of grandure.
ETA a listed judge does not automaticly mean its a good show. Our school show had a very good listed judge for the dressage but that was because she had a child at the school and volonteered. She had been briefed not to eliminate for tack and clothing etc. Infact I believe she then went on the judge at nationals.