Damage of car tyres.

I passed at BP Garage on the 04/10/2014on my way to wrk,the petrol assisted told me the is a problem with my tyre and offered to remove the nail for me and put something to closed the hole but he charged me R70,to my surprise the nail was very clean an looked new,but every time when I pass that garage I see many cars having the same problem with them removing nail on their tyres, so my question is, does every car goes there got a tyre problem? Since then I don't go to the garage, today at 7:45 I run out of the petrol I decided to pass to the same garage ,unfortunately the car behind me they were removing the nail.The petrol assisted came to help me he then tell me there is a problem with my back tyre, I told him no ways since I knew their strategy and dirty minds ,I went out to check on my tyre it was ok, I went to see the manager to explain everything but he was not willing to listen . I didn't want follow up on these, but innocent people are losing money buying new tyres and for them to gain R70.00? all the workers started insulting me as if I was talking **** in front of the manager and he did not say anything, I need this to be investigated, I want my R700 that I bought the ne