Vodacom claims I'm in arrears when I settled my arrears in November

Last year My Vodacom account was in arrears by R590 of which I paid in November 2021, since then I've been paying R200 on a monthly basis... Now I wanted to cancel the contract, they are telling me I owe the R700 and something I don't know off and they have never informed me off... I have an invoice of R175 of which I believe I owe and will be paid on the 15 as I usually do every month... I am Sinethemba Gabada ID No. ***, the number in question is ***