Check withyour HR people to find out what to do.
Normally the relocation companies defray some of the expense by charging your listing agent and your buying agent where you are going a hefty fee.
Your company is also throwing money into the pot to pick up some of the expenses. With having your home listed already the agent does not have to agree to pay the relocation comany the percentage that they desire. Your comany should have been aware of that when designing your package so check with them and see what your package is covering.