what's the most expensive item/s that you can buy at 7-eleven? just wondering in case the bank issuer questions our (multiple) $500+ 7-eleven purchases.
just trying to come up with a plausible explanation if ever. 
"they had a sale on some phones and i bought a few". if pressed, "i buy and sell them."
will this work? im not sure how much their phones are.
"i bought a year's worth of prepaid phone cards" ???
im just spitballing here. hope you guys got better ideas.