You haven’t said what ftp program you’re using, but a common ftp error from most ftp clients for out of space (Disk quota exceeded) is a 552 not the 522 you mentioned. Are you sure it was a 522 and not a 552?
I suggest you follow @NeilUK’s advice if that fails then more information would help. I would suggest you get the stand alone ftp client working first, then go back to publishing within RapidWeaver.
- What ftp client are you using?
- What is the hosting company?
- Could you give a screenshot of the error message the ftp client is giving?