Firstly what Brightmail enabled product are you running? Brihgtmail Message Filter 6, (formerly Brightmail Antispam), the Brightmail Gateway(formerly SMS 8300 appliance), or SMS for SMTP?
Do you know if you actually renewed Symantec Multi Tier Protection instead of just SEP? If that were the case then you would be entitled to run the Symantec Brightmail Gateway appliance.
The Brightmail Gateway is really the only product associated with SEP when purchased in the Multitier Protection bundle. if you have SBMF(SBAS), then unfortunately you would need to renew the licenses for that product. If that's what you were trying to do, it sounds like your vendor may have got it wrong.
Kevin