Unprofessional Service

I handed in my Samsung tablet for repairs on the screen and rear case on the 29th of October 2015. I received a quote for the repairs later that afternoon with the following instruction and demand. I had to pay the full quotation amount in advance before any work will be done and parts be ordered. Parts to arrive was given an ETA of 5 - 7 days after payment in full was received. I paid the full amount on the 30th of October 2015. After several weeks of no contact or response to e-mails and voice messages, finally got thru to one of the Directors who took charge of my case, only to be told that half the parts ordered has not arrived. Another week went by with no word or response, finally got thru again last week Monday and was informed that the final part arrived. Another week went by and went asked where is my tablet a very surprised response that i was not notified to come collect was followed. Phoned again yesterday only to be told that I will be contacted back and had the phone put down in my ear. Tried phoning several times again today to no avail. This is pathetic customer service after expecting you clients to pay in full before even considering to do repairs!!