I extend my sympathy. Do tell us what their customer service says
Had the same problem before 'apps'. The airline changed the time of departure - bringing it forward - and despite having my email address and mobile phone number, I got no information. Fortunately, on both occaisions, I was there in good time and able to get the flights.
Once it happened with a low cost carrier, fortunately I had no checked baggage ,and the other time with a full service international carrier.
So I don't trust anyone.