Terrible service

I booked in a device for service, I was advised to make a payment upon receipt of an email confirming the fee for repairs. I paid and used my device imei number as a reference as per instruction, I then rep**** to the email with an attachment of the proof of payment. It has been two weeks and no word from the service centre, I called the contact centre 4 times and they told me it has not been repaired since they haven't received any payment.