HELP!Unable to create directory. Is its parent directory writable by the server?

I’m having a little difficulty with my wordpress media upload feature. Every time I try to upload an image, there’s a message that reads:

Unable to create directory.(Followed by a series of directories separated by forward slashes)Is its parent directory writable by the server?

I’ve been looking around the internet, forums and similar topics and I still haven’t found any resolution to this problem. I’ve already checked and unchecked the “Organize my uploads into month- and year-based folders” option and that hasn’t worked for me. I’ve deleted the forward slash at the beginning of the directory in the “store uploads folder” option and also nothing. I’ve changed permissions in my FTP to various numbers as suggested in many forums but it has also failed me.
I’ve spoken to a domain and hosting representative and he ran various tests and he gave me a little glimpse as to where the problem may be. He said that the issue that seems to be occurring is that WordPress hasn’t created a folder within the wp-content/uploads folder where the images that I upload onto the site will be stored. How would I go about resolving this problem?
Thank you.