Virgin Mobile free insurance help

MysteryQ

Hi, apologies if this has been covered before but I couldn't find a search option.

I recently lost my phone and called Virgin Mobile to claim on the free insurance I was told the phone came with. They told me that because I didn't have an app called mobile rescue installed my insurance is invalid. They say I was sent a text to let me know I needed to install this app but I never received one.

My welcome letter and contract don't mention this app anywhere but do state there is free insurance as part of the deal. I have called virgin mobile and requested my information from their systems, showing any communications between myself and virgin but they said they do not keep records of text messages sent to customers and can't provide any information.

Is there anything I can do to combat this denied insurance claim? The only thing they sent telling me about the app was a text, which I never received and which they apparently don't keep a record of, how can it be legal to deny my claim based on that? There is no way for me to prove I didn't receive the text, and they cannot/will not provide proof that it was sent.