Vodacom contract

I had a contract(WIFI home internet) with Vodacom, on April or May 2025,I called Vodacom to complain about internet connection which was very poor, after few months, Vodacom technicians decided to come take my router due to poor internet connection provided in my area because of 1 of their tower. There router was collected on the 15 August 2025 after months of complaining and no assistance. Vodacom decided to debit my Account for September and October, keep in mind that Vodacom never communicated with me anything. I found out that I owe Vodacom January when I check my credit record, that’s there only time I saw that I owe Vodacom and there amount was in arrears for months n I wasn’t aware, I spoke to Vodacom and there outstanding amount was credited and I paid outstanding amount. Now when they have to cancel my contract because they can’t provide services to me, they say I must pay usage or contract cancellation fee, why? I last used there router in August why pay usage or cancellation fee? Am not happy please help