Publisher (online, refereed journal) is not publishing the volume containing my paper - what are my options? In 2010, I had a paper accepted for online publication by a refereed journal.  I was given a URL for my article, and told which volume would contain the article. 

The journal has never published that volume. Repeated inquiries (via emails) with the journal editor have produced nothing that indicates the journal ever intends to publish that volume (containing my paper).

The Journal is IJAMT (International Journal of Applied Management and Technology). It is published by Walden University. When you go to look at the listing of volumes, Volumes 8, 10, and 12 are published. There is no mention at all for the volumes Volumes 9 and 11.

At this point, I am considering submitting to another journal - however, am I 'bound' to IJAMT, seeing as they have not actually published the article? 

What are my options here?  Can I 'undo' this, and be free to submit to another journal? 

Update: Thanks for the comments, All...  I am not employed at Walden - my submission was 'external'...  There was no signed agreement.  I think I'll take the advice to send them an email... it has been a few years now, so I'm of the opinion that sufficient time has occurred.  Thanks again!  Pete
Can you find a telephone number to ring them? If not, you write an email and state that, if there is no response until [some reasonable time frame], you assume that they are not intending to publish the work, and having invested considerable time in the development of the paper, you will consider yourself fully entitled to publish the paper elsewhere. 

Note that I do not know what the legal situation is (this is not the place for legal questions).

However, as per Dirk's suggestion, I add that universities have a legal department that might offer legal advice on such topics, as long as OP is employed at one.