Paid cash but No service rendered

Hi Please help, my granny paid for erecting of Tombstone from Valley Tombstone in groblersdal on 18 January 2021and even Today they have not erected the Tombstone regardless of endless visit to the with empty. Last visit to was 18 days back that's when they promised to erect the Tombstone withing 14days but even today still nothing and they do not want to refund.