False advertising

I have a bad experience with Orderin,and i dont think i will use them ever again. my colleague ordered via orderin, and they got the promotion discount code that was supposed to be passed to the next person, and he gave it to me. when i tried using the code for my lunch at work on the 8th of March 2018, the code didn't work, even though i was a first time user of Orderin. i called the call center to help me fix the error promotion code, i was on the telephone line for more than 30 minutes, were the call center agents was trying to help me, but with no success. he told me he was going to call me back, as their I.T department was resolving the issue. that was twenty past one, lunch time at work. they never called me back and i never had my lunch as my lunch break finished while trying to use the app. Till now i haven't even got a response from them regarding the issue.