Why can't they just admit the mistake?

I saw this story posted. Briefly it is about someone who noticed a charge from Bezeq International for a charge for internet services the person claims she never ordered. She claims that she simply called one time to ask for information about the advertised Internet deal. She never signed up.
She looked back on a years worth of bills and found the charge monthly. She called to complain and after being given the run around and involving consumer advocacy groups, BezeqInt finally agreed to return her money.
When they returned her money, they did not say it was a mistake or a misunderstanding of some sort. They did not say we are sorry we took your money without your agreement to purchase. they said (after being threatened) that since she never actually used the service and was unhappy they would therefore refund her in full.

The article goes on to teach us a lesson from the story that we should be diligent in checking our credit card bills and make sure everything you are charged for was actually purchased by you. It is a good lesson and I have found mistakes on bills and it happens every now and again. We are all human and people make mistakes. If you do not check, you are throwing away money.

I see a different idea in this story. Why did BezeqInt have to insist on not returning the money, after having been confronted. They knew the money was not being taken properly. Maybe it was initially a mistake or misunderstanding (maybe she called for info and the saleperson thought she agreed to the purchase), but they knew after she confronted them.

The reason they agreed in the end to return the money was because they were confronted by a powerful group with the knowledge that purchasing such an agreement generally entails filling out forms and credit card info and the like and if they insist she agreed to the purchase, they should show the forms. They knew they were caught, so they had to agree.

Why can't they be honest? Barring that (if that is asking too much from a service provider), once caught in the act, why not apologize for the mistake? Why insist that you were right but will be generous and return the money?
Honesty and forthrightness would make them look all that much better. Just say, "We are sorry for the misunderstanding. the salesperson made a mistake thinking you had purchased the plan. We realize you did not and will refund your money." That's it. No need to look righteous.

Simple honesty would do better.