I have not receive my iPhone 6 plus since went fro repairs from 8 December 2017 till today

I have send my phone for repairs from 8 December 2017 till today 26 January 2018. I was informed on the 4 January 2018, that i will received my phone on the 8/9January 2018 after I was notify that it required R6000 to be fixed. I notify them that i won't be able to pay such money however I request my phone back. The invoice number 7263,

The technician and the manager don't know when i will receive my phone. HelloPeter could you kindly help