want my phone and sim fixed

i have been having problems with cellc every since i got my contract phone from them. from not being able to make calls because i have reached my limit which i do not have a call limit, to them making me increase this limit by R250 every-time i want to make calls or sms. my sim was not working had to do sim swap which i did and was charged in cresta mall cellc. but i used they works phone to call customer service. my sim has not been working went to cellc mall @reds a guy called Eslenne Opperman who told me my line was blocked because i reached my limit and i should upgrade. every-time i seen to deal with cellc they just want me to pay and pay and just give me **** service back. i do not understand how a line can be blocked if the money is debited every month from my bank account i am really frustrated with cellc i wish i could just cancel my contract with cellc. they have done nothing but frustrate me since i got this phone and been experiencing nothing but grief. and the second phone they replaced my phone with is **** it does not even play when its pluged to apple devices it is not readable. i am really counting down to the day my contract ends.