Some mobile phones just do not support MXit.
They could be too old or not have the right software or hardware to run it.
Or the phone could have some issues that make it impossible to run MXit.
A phone needs to have JAVA, GPRS and a Colour Screen.

Here are the phones that unfortunately don’t work with MXit:

Motorola
A6188
ACCOMPLI 008
ACCOMPLI 009
ACCOMPLI 009
ACCOMPLI 388
C113
C113A
C115
C115
C115
C116
C118
C139
C139
C168
C200
C205
C230
C250
C257
C261
C289
C300
C331
C332
C333
C336
C350
CD920
CD930
D520
E360
E365
E390
M3188
M3288
M3588
M3688
M3788
M3888
SlimLite
STAR-TAC 130
STAR-TAC 75
STAR-TAC 75+
STAR-TAC 85
STAR-TAC Rainbow
T180
T190
TALKABOUT T 2288
TALKABOUT T191
TALKABOUT T192
TIMEPORT L7089
TIMEPORT P7389
TIMEPORT T250
TIMEPORT T260
TIMEPORT T280
V.BOX (V100)
V150
V171
V2288
V290
V291
V3688
V3690
V50
V60
V60I
V66
V66I
V70
V8088