Fustration cellc told me I'm owing R2700

I love cellc but to me and last year they never be nice to me, i don't know it cellc is a **** now, some 1 or2 months i never paid, so the issue starts they told now i have subscription on my contract i suppose to pay R350 or R400 instead of R200 as per my contract , and month june they said i never paid the ask me to send bank 6 or more bank statements i sent it, i did a follow up they said they said they sent it to the financial department, they give me case number and they said they get back to me... While on another arrears increases, i ask them to stop it till they told me if they received my statements, till now they never get back to me.... Now im handed over they said im owing R2700 how come cz i sent statements on emails they gave me.. So now i don't know what to do, and when I'm calling cellc different consultants they told me different stories.