Instant life policy application

I app**** for life cover 06/05/19 and was told will receive a call the next day to from assessors but nothing. After many client services emails in which I've sent the agent who initially called me for the application called me back to tell me my application has been declined. I subsequently asked why application was declined he reciprocated by saying he does not know why. I've since app**** with another institution, for them to carry on with the application they need to know why I was declined by your institution and the answer is just not forthcoming.