Is it wrong to decline?

I’ve been giving help to a not-so-closed friend for a few times. Don’t bother if there is a ‘thank you’ given in return.

Thing happens when once she gives some possibilities to make her regular request a success. However, I standing to decline due to a ‘really not free’ reason. She treats me as a transparent object ever since this incident. Is it wrong to decline somehow? Only once… …

Perhaps,

• She only thinks for own benefit? take it all for granted. Wondering… … Does she have self-criticism on her attitudes? Selfishness reflected in the way ppl communicate with one another.
• Adult should have learned on the manner in communication.