Modus Operandi of 7-11 or innocent mistake?

[gearhead]

I sent my driver to buy me something at the 7-11 of the Sagittarius bldg on Dela Costa Makati with 100 pesos. He then came back and it appeared as if they shortchanged him and insisted he gave 50 pesos. He got confused he said at the counter and was unsure so he thought he had be given proper change. My driver is generally trustworthy and it could be said he was skimming me but he never has and has even been trusted with larger amounts. Was 7-11 trying to get away with a skimming scam? Anyway for what it is worth I am sticking to the ministop across and will stay away from that 7-11.

For whatever it is worth I asked the others in the building and they had a feeling the place was dodgy.