Bad communication regarding stock

This is the third time I have been to the Samsung store to purchase a Samsang Galaxy Grand Neo phone battery. The first time I phoned the contact number on the internet but there was no answer so I mailed them and asked if they had stock. They rep**** to me that they do have stock. I told them I will pick it up the same day or the next day. When I arrived the next day the gentlemen told me they do not keep stock of the grand neo. He said he thinks the S3's battery will work but he is not sure. I should bring the phone so he can check. They had stock at the time of the S3. The second time I brought him the phone so he could check. Again the batteries was out of stock. They said I should come back the Saturday. This is now the third time, still out of stock. Now he said I must come back the Wednesday which will be th fourth time. Now he suggests I should go to Menlyn. I told him he should take my details because I am not going all the way to menlyn.