Error on cgdcont

Whatever I try I can not get the Q24PL001 to accept any settings to the GCDCONT Parameters.
Firmware used is
AT+CGMR
657g00gg.Q24PL001 1972992 102208 17:08
Modem is recognised as:
AT+CGMI
WAVECOM MODEM
AT+CGMM
MULTIBAND 900E 1800

Issuing the command:
AT+CGDCONT:1,“IP”,internet"
ERROR

I proceed to test other commands to get the settings:
AT+CGQREQ?
ERROR
AT+CGQMIN?
ERROR
AT+CGATT?
ERROR
AT+CGATT=?
ERROR
AT+CGCLASS?
+CGCLASS: “B”

I try to change the Class:
AT+CGCLASS=“CG”
OK
AT+CGDCONT=1,“IP”,“internet”
ERROR
I change back to the previous Class:
AT+CGCLASS=“B”
OK
AT+CGDCONT=1,“IP”,“internet”
ERROR

WHAT MAY BE THE REASON I CAN NOT SET THE +CGDCONT PARAMETER NEEDED !