Manpower labour

This Company contacted me on Friday for a delivery of posters. I asked them not to deliver the posters because the person in charge is not here they must come on Monday still they delivered and I paid them R2500. So on Monday I phoned them back it was a mistake we did not ordered the posters and can we return them and get a refund I personally spoke to Temara asking her to assist she does not reply and doesn't want to help resolve this matter. I also phone the office number spoke to Charmaine if that is really her name and she said she cannot assist. The first time I phoned Temara she said her name is Stacey only to find out from Charmaine her name is Temara how can you deliver such service