Its very bad

I'm feeling bad about what happened to me, i took a phone frm 2018... Due to covid i was paying cash instore monthly... Then my contract was supposed to end in September but i couldnt due to late payments interest.. In october i managed to pay the pay last payment and nobody told me i hv to cancel the contract, i went to westgate store to pay cash but they did.. After few weeks when i log in my ma vodacom app, i find that m owing 433.00 i called the call centre nd they told me if i ddnt cancel they continue billing me as usual... The invoice include the phone amount while i finished the phone last month.. The insurance as well... Cant you check if the contract has ended and stop billing us please i feel like they have cheated me. Coz ds month m gonna b paying insurance nd handest while the phone contract its expired already.. Mxm