Service problem

Husband is working at a construction company and need to get hold of the workers. One of the workers lost his phone and did a sim swop waited 24 hours for sim swop to complete on the following number ***. After the sim swop my husband could not phoned him, when he phoned him then the number automatically go to line busy. After 3 days we did a sim swop on my husband number *** waited 24 hours and still the same problem occur, vodacom customer care also did network syncro****ng, we thought that the sim swop would have resolved the problem but the same problem occurred. Service request was loaded at Vodacom The Bridge and it was closed because it is not a network problem. No numbers was blocked on both number, numbers was deleted completely form both device and re-inserted and still same problem. This is very frustrating not to get one of the workers on hand for a site. There needs to be a solution to this query. Please feel free to contact me on ***