Withheld my money...

I have been financially affected during this COVID period, and I informed Cellc about my situation however they stated that they cannot assist me as I was supposed to have came forward when they started to assist other customers although I was unaware and was able to pay my monthly payments without a problem it was only one month where my UIF ters took long to be paid, that when I contacted them but did not get and assistance only rude consultant. I went to Cellc southgate to ask how much should I pay as I was only left with two month to finish with my contract, the consultant went to her system and wrote the amount I should pay on a paper which also had Cellc banking details to go an make payment and only then I can close my contract. I did that, and called them to close the contract of which I was told to send the proof of payment which I did, then I called again to continue and cancel my contract. The gentleman whom assisted me to cancel it was very professional and assisted me very well. The problem started when, they sent me an invoice the following month with a closing balance of about R159.02, I immediately called them to ask about it, then I was told that I over paid my account when I canceled it. I then asked for my money back because it's their consultant whom gave me the wrong amount to pay, since then I have been asked to send proof of payment all the time I enquire about my money, and I always send the proof of payment and they give a ref number. When they need their money they do not care where you'll get it from they want you to pay regardless of the circumstances, now since its them whom owe me they are giving me the go around. Cellc must pay back my money.