Pathetic service from Cell C

Unable to receive calls. Called Cell C on the 7th June '19, advised them that I am unable to receive calls from other networks. Consultant called me on my number and I advised that I can receive from Cell C but no other networks. Called back and they reset the settings. Still cannot receive calls. Called again and logged a query which they advised will be resolved in 2 working days. On On the 9th June '19, received a miss call and thereafter a sms stating that the query is resolved. I called Cell C again and spoke to the manager and explained the entire situation again, he undertook to look into the matter and revert. After 5 days I still cannot received calls from other networks. This is in breach of the contract. I will now report the matter to ICASA and request that I cant be billed for this contract. Furthermore, this is a business contract.