No delivery since 15April2015

Still waiting on delivery of goods paid for on 15 April. Every time I call there call center they can't help me and never get back. The one time I did receive a call after my first complaint I was told 2nd week of May by the latest. At this stage I don't know what to do anymore, except get lawyers involved. Any one with suggestions on how I can get what I paid for more than a month ago? I have already wasted so much money just waiting on there call center. Can't believe a company can be this useless and not get back to customers.