What is the ruling on working in a mobile phone shop if colleagues smoke and listen to music, and this cannot be denounced to them for fear of dismissal?

There is no impediment to working in mobile phone sales, provided there is no participation in or assistance with forbidden acts, such as downloading forbidden ringtones and songs. The ruling on your work is not affected by your colleagues smoking or listening to music, but you must denounce them according to your ability. If you fear fitna (temptation/strife) for yourself, then it is obligatory to leave this work immediately.