readability – Table cells: verbose or abstract?

I have received a surprising feedback from a large number of my users on something that I would never consider a problem. If the number of votes on this particular return was not so important, I would not consider it relevant, but now I guess my intuition.

In my product, there is a table / matrix that displays the flights and their attributes.

The lines represent the types of flights available:

Rate A
Rate B
Rate C

The columns represent the flight attributes. The header line literally reads:

Rate Name | Refundable | Free checked baggage

It is important to note that it is a very small matrix, with no more than 5 tariffs (usually one or two) and exactly 3 attributes.

The cells in the table show

Yes No

for the refund, and

0/1/2

for free checked baggage.

As we said, it's a small table that still stands on one screen.

Feedback indicates that cells are confused and difficult to interpret.

Instead of the refundable cells displaying Yes / No, the return of information asks the cells to indicate: Refundable / Non-Refundable.

Instead of 0/1/2 for checked baggage, the cells must indicate: No checked baggage / 1 checked baggage / 2 checked baggage.

As I said, I am really surprised by such feedback. Myself, I would never see a problem, but I may have missed a trend or an important study?