Unfiltered Story #247789

My store a few years ago started printing coupons at the end of receipts, for 10 euro off a 50 euro spend, and to get the coupons, you had to spend 50 euro for each one.
A couple months ago, a new coupon was added, good for 1 euro off a hot drink in our newly built cafe.
Note, that the two coupons look 99% identical, beyond the part saying what they are good for. They have the same font, the same type of barcode, in the same position, and even the same terms and conditions in small font below, which is just bizarre (what’s the point of a 1 euro off a coffee coupon saying you can’t use it with lottery tickets?).
A lady comes through my checkout with her weekly shopping. I scan everything through, and she hands me four coupons. The last one has the part just above the barcode ripped off, and so I take it by default to be a 10 off 50 euro, just like the other three which are undamaged.
However, the last coupon doesn’t ring through. All my register tells me is “Insufficient Spend”. I look through her receipt several times, trying to find out if anything she bought doesn’t count towards the 10 off 50s; but no, everything checks out.
I call over a supervisor. They’re baffled too.
The manager gets called over: baffled too.
Finally after about fifteen minutes, the lady just says to void off her last few items (which she got only to get over the 200 euro requirement for using four vouchers), she paid and left.
After all that, which took the better part of about 15 minutes, does my supervisor come over and tell me that the last voucher was in fact a coffee voucher, which is why my register refused to take it.
The woman, in our estimation, was trying to pull a scam on us.