stk topup: sim balance not working using huawei e303

I am unable to check my topup sim balance using huawei e303 usb dongle it return error whenever i try to send following command

i tried to send input by pressing Ctrl+Z from my keyword also i tried with pressing enter only from keyboard neither option working...

anyone can show me how to exactly pass/input command using huawei e303 modem?

AT
OK

AT^STGI=0,0
^STGI:0,1,"455253"
^STGI:128,1,"5072657061696420546F705570",0,33

OK
AT^STGR=0,0,1,128
OK

^STIN:6,1,0
AT^STGI=6,
^STIN:6,1,0
1 ^STGI:0,6,"5072657061696420546F705570"
^STGI:1,6,"5265636861726765",0
^STGI:2,6,"506F737470616964",0 ^STGI:3,6,"4C617374205265636861726765",0 ^STGI:4,6,"53746F636B2042616C616E6365",0 ^STGI:5,6,"4461696C79205265706F7274",0 ^STGI:6,6,"4368616E67652050494E",0

OK AT^STGR=6,1,1,4 OK

^STIN:3,1,0 A ^BOOT:5606864,0,0,0,20 T^STGI ^STIN:3,1,0 =3,1 ^STGI:"50494E",4,2,0,0,3,6,0

OK AT^STGR=3,1,4,9865 (Ctrl+Z) OK

^STIN:99,1,0