This used to happen to me since my MP# had both of my names and my reservations only used my first name. I even got one reservation with my second last name and the miles still posted BUT:

- you will have to add the FF number in the united web page reservation, if you see it in your profile then when your are giving the boarding passes the FF number should be on them giving you your privileges.
- regarding the RDMs, bonus RDMs, and EQMs, they won't post on your account until you submit it online. When you submit the request online add a copy of your passport or ID with both names and explain that the travel agency screwed up on this reservation. You should get an answer in the first 24hrs that the miles have posted to your account. If you don't get an answer in the first 24hrs send another request, I never waited for the 14 day rule and submitted tickets until I got an agent that was willing to the work.

Hope this helps.