lack of service and dishonesty

i went to pour petrol and oil at the Conrad Drive service station and when i paid my account was debited twice this was on Monday i told the manager he said it would reverse i went back on Tuesday was given Prospers numbers whose the manager there, even today he has not returned my calls nor has he communicated with me. i gave them my bank statement to show them but nothing has happened. now the manager is nt taking my calls. I have sent him numerous messages to his number *** HE DOESNT EVEN PICK UP MY CALLS!!!!!