HOW DO YOU KEEP A CUSTOMER ON THE LINE OVER 15MIN

I am highly disgusted by the service of Clicks Greenacres. They kept me holding for dispensary for over 15min without once saying...\ thank you for holding but there is no answer ... is there anything I could help you with\"... How do you keep your customers on the line for so long and put through a holding call without giving the customer the opportunity to say ... ITS OKAY ... I WILL CALL BACK LATER??/.... Clicks need to up their game as far as customer service is concerned... WHAT DOES YOUR CSI scores look like?????<br> I would just like to know the price of your ACCU-CHEK STRIPS please ... The green and white box and the maroon... <br> <br> TOTALLY DISAPPOINTED"