First of all, you don't need to compensate the unit cost. Because according to what you said, the unit didn't actually pay you the training fee.

Secondly, even if the company pays for training and other expenses, the amount of compensation you need after leaving without reason cannot exceed the amount paid by the company. The agreement to pay ten times the compensation violates the law and has no legal effect.

Finally, the issue of salary, if there is an agreement in the contract, will be dealt with as agreed. There is no agreement, no need to return it.