refusing to take all three of the most common spending tools (cash, credit, debit) is poor customer service. the vendor is telling you that he's doing you a favor by taking your money. :hunf:
checks can bounce so we shouldn't fault a vendor who wants to protect himself from shady strangers.
if you lose cash, it's gone. if you lose your debit/credit card, a quick call to bank security will protect you from fraudulent charges.
i save up and set a budget before i go. i carry only enough cash for incidentals such as snacks and meals. the rest goes on plastic. i track the charges against my budget. when that's spent, i stick to window shopping. when i get home, i send a payment to the card company to cover what i spent.