I take a bus to work. Sometimes one or even 2 buses don’t show up or the wrong number is shown in the window so I don’t get on the bus and therefore I have to take a taxi to work to get there on time. Can I not pay them when I can get away with it like Motzaei Shabbos from the Kosel.etc.
No. Although they are supposed to provide a regular service, you have no personal contract with them, and so technically speaking they don’t owe you anything. If they don’t show up, they are not Halachically obliged to pay for your taxi. However, try contacting them directly, and request compensation. If they are willing to give, you may certainly accept!