Calendar - unexpected error has occured

[Guest smartpicture]

My 3-wk old SPV M3100 (HTC Hermes) was working fine, but suddenly lots stopped working.

1. Calendar - I get a message saying an unexpected error has occured in this program

2. Phone - Nothing happens when I choose this, nor if I clcik on the green handset button, so I can't make or receive calls (altho I have a signal & can make & receive texts)

3. Tasks - I get a message saying No program memory available, tap start, settings, system tab, memory, stop programs that did not autmatically stop and try again. I do this, and v few programs are running with lots of memory free, but stopping them makes no difference.

4. Contacts - Shows the Contacts and Speed Dial buttons, but nothing happens when I click either of them

All other function seem to work: texting (but doesnt show contact names), games, settings etc.

I've taken out the battery and started it again but still the same. What else can I try? I've never had a Windows Mobile phone before. The shop just says i need to send it away which is a dreadful prospect!!