***** on my policy document

I paid the full amount of R7862.11 for service plan of 45000 km last year may 2019 at liquidcapital and the same year around November i took my car for a service of 135000 km and they paid for it and on the 15 july 2020 when i take my car for a service for 150000 km ,they denied the dealership an authorization and said there is shortfall on my policy,i then phone them and they told me that i have cancelled my policy and i must forward proof of payment.i have lost proof of payment and they say they are unable to trace it on their system but they can see that i have paid the full amount and suprisely so is that they have managed to pay the service of 135000 which i have covered for and never requesting proof of payment but today after a year suddenly proof of payment is needed