I just joined the server and baught a nade pack from the /shop menu!!!
There is a /shop menu, which is legal for all. If the guns you used were the nade pack (10 points per one in /shop), then snowman banned you wrongly.
You could have used/thrown the nades at HNS before 4:00 though, but it would not have mattered at all, because CT's have godmode then.
The original gunshop, where people usually buy guns, that cannot be found around any map (autosnipers, famas, galil and others) and bought from the original shop - for that case guy is issued a rightful ban (only if such abuse has been done multiple times - after issuing a warning as well.
About swearing - it's normal in the server, you'll get used to it.
Good luck!
P.S Let's wait for Ultor's comments.
2nd P.S - It's only a 1 hour ban. Even if you might have been banned wrongly, you can talk, and I mean TALK, not FIGHT about it with Ultor/snowman after that time.