It shouldn't be. It's disculpe for people you address as usted and disculpa for people you address as tú. The hint here is that Ana is referred to by her given name and asked for help with the tú-form "ayudas".
To use disculpe, it would be something like:
Disculpe, señora de Armas, ¿me ayuda?
Also, try listening to both normal speed and slow. Sometimes one will have the "s" sound and the other won't. That usually tells you that there's supposed to be an "s" sound, but it got clipped in one of them. Rarely will an incorrect sound get added to one and not the other.
NOTE: "Disculpa," which is imperative, is not likely to be followed by another imperative. Just as in English you wouldn't say "Excuse me, help me." Now the speaker is asking Ana to help him or her, but not using the imperative. This calls for present tense, 3rd person singular, informal: "ayudas," even if you don't hear an "s." As another example, if you hear "los año," and you're sure about the "los," then it has to be "los años," even if the "s" is dropped. Sorry, if I over-explain.
Well, even then it could be a listening exercise, so let's be open to that unless they say otherwise. And, it could be that "Ana"/"Anna" is a non-Spanish person and there's no rule saying someone Spanish can't be named with two successive N's so let's be open to that as well.
The original statement is a request. The speaker is asking if Ana will help him/her. We often say "Can you" or "Will you" to make such a request. "Do you" is not suitable for that. It sounds awkward. It is asking if Ana is now helping the person, but the wording is unconventional.