Paying for a contract i cannot use

MTN will not allow me to upgrade now they want me to wait till july even thou my current phone on the MTN my choice 100 contract no longer works and I am basically paying for a contract I cannot use I will not go and buy a new phone why should I incur an extra expense I have called them numerous times and all I get is we cannot upgrade you early and we will send a mail to the retentions department to assist you I need a phone for my job as I meet clients yet when I explained this to them all I got was sorry cannot help you I am so sick and tired of MTN i am not asking is for a miracle i am asking for an early upgrade which will only be 2 months earlier than my scheduled upgrade yet they refuse to help to me it looks as thou they don't care about their customers. I would really appreciate it if they could help me upgrade now to save my job