R & L Fire Protection

Last year as a general contractor I hired this company, Raul, to service a building in Pasadena. They were on-​time and priced very reasonable.
I just learned that Raul and his team did a «service call» at this same building this month and charged the client directly. The client paid the bill thinking I approved the work. This confusion led to unhappy clients on my end.
I called Raul and was promised a return call. That never happened. I phoned again and Raul stated the «service call» was automatic. I explained to him that I, the GC, was the client since his contract was authorized by me and I paid him the first time around. He emphatically stated «That’s how we make our money».
My advice/​warning… If you hire R&L Fire Protection go into it with the understanding that they will be back without your permission and strong arm you to pay. I see this as unethical and quite frankly illegal. Consider yourselves warned :)