Porting or and unblocking sim slot

Im have a big problem with cell c. For almost 4 months I am trying to port my number from Cell c to Melon. Im suppose to get a OTP from Cell c to be able to port to Melon, but they are just mot sending me the OTP. When i phone they are unable to help me. I then decided to unblock my sim slot witch was blocked when my phone got lost, luckily i found my phone and want to unlock the sim slot to be able to use two sim cards as i they cant seem to port my number. But that is also without luck. The guy at cell c said that it will take 25 to 42 hours, its now over a week and still jo luck, went to the cell c store twice al ready, they cant help me as cell c need to phone me im jot getting phone calls from them, i phoned cell c customer service in the morning the lady asked me to phone back she will be able to help me i must just provide her with the imei number. In the afternoon i phoned back with the imei number, just to hear that they cant help me because cell c dont have the unlock code as they dont have that brand phone unlock code, because they dont sell that brand, ironically i got that phone from cell c. I am so tired of this. All i want is to port my number or unlock the sim. I cant understand why cell c cant help me with this. And i dont get that i have to struggle this long to get it done. Its unacceptable.