Concern with relying on text messages; I had blackmail text messages sent to me on my mobile in case on a future issue with the authorities. The issue did arise but unfortunately issues with my mobile meant it would not switch on.
I tried numerous businesses to try and retrieve the messages but none could access its storage. I gave the Solicitor and Police all the information but they did not go to the ISP to ask them for a copy - in the knowledge a mobile phone operator only keeps records for a year.
My advice is to see if you have the software to backup or view your mobile phone text messages then either print or screen grab a copy - ensuring you include relevant dates etc - of them for retainion.
I hope this helps as nothing beats a hard copy.
Learn from yesterday, live for today, hope is for tomorrow else what is left if you remove a mans hope.