Contract at yelkom is bad

I had 2 lines for internet with them in 2018-19 prior to covid . They stole a lot of cables in my area so the technical support told me that the would not be replacing the cables and that they can cancel my contract with immediate effect with no cost to it. They proceeded to cancel both in the same time and now after 2 years I get a call from lawyers saying I owe telkom money why on just one account and they were both canceled the same date and for the same reason. This is absolutely unacceptable I refuse to pay something they canceled and said that there is no cost involved and still till today have not received one bill for this ?