FTP Authentication Failed

I am setting up an integration with a third party- created my own .csv file, was given a WinSCP logon credentials and successfully manually uploaded the file on their side. Now in setting up the automation in my peoplecode, I am getting authentication errors even through I had successfully logged on with the same credentials as in my URL.ID in my putattachment() function. My code connects to their address, passes my username with success, initiates the password, and fails authentication(530). Why could this be? Is it on my side or theirs?

220 Service ready for new user.

> USER some-college

< 331 User name okay, need password for some-college.