Lady Returns Salary Mistakenly Paid To Her Account By A Company She Did Not Work For

I WAS PAID SALARY FOR A JOB I DID NOT DO AND I'M RETURNING IT.
I have been in lagos for some months in search for job, I have applied for jobs and still applying for jobs, gone for interviews and then in April I got a job as a telesales representative with a Fintech #Opay Nigeria through an outsourcing firm #HR INDEXX. I already filled in some of my details in which my account details was part of but for some reasons I couldn't take the job offer.
People who took the job offer are 1month on the job and were paid salary for the first month yesterday, I also got a credit alert meaning I was paid by the outsourcing firm for a job I did not do.
I have waited for the transaction to be reversed or to get a call from HR INDEXX but none seems to be coming forth. Therefore am going to the outsourcing firm today to return the money and to let them correct their payroll.
NO, I haven't gotten a job yet, am still unemployed and searching.
NO, I didn't get salary from any source in the last month which means I need money but my desperation for a source of income will not rule out the conscious need to keep my integrity for the long run.
Yes I am a Nigerian.
Yes I am an Igbo girl
Yes Nigerians still up hold integrity.