1. Did you verify from backend that the org is created (query hz_parties table for the return party id from the API)?
2. Hope you have passed COMMIT flag as true for the API or explicitly committing the changes.
Check if the TCA screens are using DQM Based search , if yes goto Trading Community Manager->Administration->DQM , see if the DQM Syncronization method is not realtime ( Batch or Disabled). If its batch run "DQM Syncronization Program" to have the newly created record visible through DQM Search.