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I have a Sony Ericsson W595 and people have been having problems phoning me.
They say the phone message says unavailable even when I know I have good signal.
Sometimes my phone does lose signal at odd times and the phone feels unreliable.
What should I do?
If you get the same problem everywhere, your first course of action would be to eliminate whether your have a phone or SIM card fault.
If you can, try your SIM in a different phone and, if possible, let someone else try their SIM in your phone and see if you still get the same problem.
If you cannot try the above, take the phone into a Vodafone store for them to test with one of their SIM cards. If necessary, they will arrange for your phone to be repaired or, if you have a SIM fault, issue you with a new SIM card.