CAN USA Rope Access Tech interview questions

I've on occasion sent my resume out via email to RA companies I've located on the Internet. On two separate occasions now the main office located in Harvey Louisiana has called me, conducted phone interviews and with verification of my certs and references have hired me for a job offshore. Job of course pending upon my ability to pass a drug test. I've on 2 occasions been told to show up at the La Porte TX office ready to go offshore for extended time. I have traveled 5 hours from Paris Tx, and on the first occasion took and passed my drug test, to be told to stand by that the job was going out in the next couple of days only to never get called. Once, I could understand as things in this industry are. But for them to done this twice in a row with no explanation or regard for travel time, effort and money spent by new employees is unexceptable. I've chosen to not answer their calls anymore as I'm sure they would fire an employee who no called or no showed.