Appalling service from Incredible Connection

I have received appalling service from Incredible Connection, Cresta Centre. I handed in a D-Link modem which was purchased on 20/08/2018 from them as it was not working, to be informed that it had to be sent for repairs and would take anything up to 14 days to return. I insisted on a loan modem to use in the interim. I returned on the 16/11/2018 to be told that it had not been returned from the supplier!!!! I subsequently reported my dissatisfaction to Incredible Connection Head office (0 ********** 00) on Friday 16/11/18 and was informed that someone would call me within 24 hours. I did however received an e-mail with Reference No. 741178 I called back on Monday 19/11/18, Tuesday 20/11/18 and Wednesday 21/11/18 and on each occasion was told that they would escalate the complaint but by the end of day I still have not heard from them - very disappointing from such a reputable company!!!!