Vodacom can't access my contract and now it's my problem

I've had my number with Vodacom for 22 years, upgrading my contract as time went on. At one point I was on the Red VIP contract or something and this contract expired in February 2022. Since then I have been unable to upgrade, downgrade or cancel my contract. The web site tells me to go to a store, and the store tells me to phone a number, but the number tells me I'm on an old system, they don't have access. So what now, I just keep paying indefinitely because you changed systems? Sort this out, please