the reasonable interpretation is that 'or' implies the customer's choice.
I completely agree with you. If I go to a restaurant and it says on the menu that an entree comes with potato or rice, most people would expect that they get to pick which one, not that the restaurant decides for you (unless it specifically said "Chef's choice").
And in the customer service area, if something is/was vague, the decision should be in the customer's favor.