I bought the expansions like 4 or 5 days ago and I'm still unable to use features like the full trading post and stuff. How do I go about fixing this?
You wait. Some features are time-locked for new purchased accounts.
You can read about it here: https://wiki.guildwars2.com/wiki/Account#Time_requirement
yeah that is crazy. this account was made like 3 or 4 months ago i believe and started playing like 9 days now. bought the expansions 4 or 5 days ago. people say it should be really soon like the same day. but i made a ticket and await a response.
It doesn't matter when a Play4Free account is made, the restrictions are only counted from the day of purchase.
The CS Team won't lift the restrictions, and the time will probably pass before then, anyway.
Again, good luck.