The company hired me on a 4 month probation period. They paid relocation expenses and made me sign a contract stating that if I leave before 18 months, I'll have to return the relocation money.

After the 4 month probation period, they did not confirm me, neither did they extend the probation period. Around the same time, my boss repeatedly expressed dissatisfaction with my performance. I found another job and left the company after 5 months since being hired.

Given that they did not confirm me after 4 months, nor extending my probation period, and therefore keeping me in limbo state, can that be considered grounds for not paying back the relocation money?

If you were hired on an enforceable employment contract, I'd suggest taking that contract to a local lawyer specializing in employment contracts.

He/she should be able to advise on if the contract is indeed "enforceable". These matters do not have general answers. The answers are specific to the contact.

What do you mean "they did not confirm you?"

By "they did not confirm me", I mean that they did not notify me that my probation period is over.

I very seriously doubt that would be sufficient to void the agreement. But only an attorney in your state who has read the agreement in its entirety can say for certain.

I agree with cbg.

However, a few more questions:

Does the contract mandate that you must be notified that you are no longer probationary after four (4) months?

If so, what, if any, penalties does the contract state for failure to do so?

Does a "just cause" provision kick in once you are considered no longer a probationary employee?