What is the ruling on remaining in a job that causes religious and worldly problems, given the existence of a debt to the employer, and a desire to leave the job to complete studies and help the family?

You must repent to Allah Almighty for transgressing against the store owner's property and return what was taken from him or seek his forgiveness. It is not a condition to inform him that you took it unjustly; rather, it is sufficient to return it by means that do not lead to corruption or embarrassment.

If the work is unlawful, it is obligatory to abandon it except in cases of necessity. The advice is to look for work that does not harm your religion and to prioritize the soundness of your faith over your worldly life and the worldly life of others.