All Realtors go by a Code of Ethics and Standards of Practice. It is available on line, the public can access a copy of the 2014 version as a pdf file.
Stadards of Practice 1-6 states "Realtors shall submit offers and counter-offers objectively and as quickly as possible."
Standards of Practice 1-7 states "When acting as listing brokers, Realtors shall continue to submit to the seller/landlord all offers and counter-offers until closing or execution of a lease, unless the seller/landlord waived this obligation in writing."
Not knowing the details of your situation, if you think the Code of Ethics has been violated by a Realtor, you should contact the local Board of Realtors to make a complaint. The local Boards all have a grievance process they follow for such complaints.