Scandalously slow Samsung service

At end December 2017 I took my Galaxy J5 Prime to Samsung Century City for the screen to be replaced. I paid cash for the quote and was advised that quote for repairs will be mailed to me. I advised the repair centre to continue with repairs and I deposited the full amount for the repair into the account on 9 Jan 2018. Until today 24 April 2018, I have not yet had my phone returned to me. This is totally unacceptable. The level of service and feedback at Samsung Century city must rate as the worst anywhere in RSA. On the few occasions that I have managed to get a reply from the contact centre, the same old lame excuse of "waiting for spares" has been trundled out. I have been to the repair centre but that was just a waste of time and money. I have spoken to Durelle but she gave out the same old no spares excuse. I managed to extract the owners name and number (Elcardo ********** 546) from Durelle, and have tried on numerous occasions but either phone is switched off, or the voice message I left, has been ignored. Now I understand why there is never an answer from Elcardo....he too, has run out of excuses. The only times that I have received any response from this company, is the computer generated response, thanking me for the email received. Never once has anybody from this useless business contacted me with an update or an apology. How does Samsung explain this utterly pathetic service to which I have been subjected. How is it possible for Samsung, a brand of global proportions, have such a poor level of customer service, or is it confined to the general apathetic RSA way of doing things! I am waiting, with bated breath, a reply from anyone connected to this business about the duration of my phone repair. I do NOT want a computer generated reply.