Thanks Jim!
I have since realised it is doing this in or out of the holder
one of my sons friends suggested I turn the setting to 2G as leaving it on 2G/3G auto may be the problem.
I can call and I get a "call forwarded conditional"message

and call goes through but if I leave the phone for a while and call it it goes straight to message and a bit later I get a missed call on the BB
my PAYG sim is probably 15 years old and I called them today re compatibility and a new SIM. they said £10 please. No thanks, going down the orange shop tomorrow as I can get a PAYG SIM for £1 and BB service for £5 a month and keep my number. T Mobile wanted me to change to contract AND loose my number!