Refusal of Regularization

I was hired last March 15, 2018 my probationary contract will end on September 14, 2018 and my contract says I cannot refuse upon regularization is this legal?

what do you mean refuse upon regularization? what will you be refusing after the probationary period?

the key word here is "upon". you are asking a question with some info omitted. kindly re-phrase the question so you can get an accurate answer.

Are you prohibited from refusing the end of your contract? Or prohibited from refusing being regularized?

I don't see any reason why you should refuse being regularized, though. But they cannot prohibit you from refusing the end of your contract, because probationary employment may be ended only upon showing that you were not able to meet the standards of work required from you. https://www.alburovillanueva.com/types-employment-affects-security-tenure-2 It does not end simply because a certain date in the calendar has come. Was there a performance evaluation that shows you to be unfit for regularization? If none, then you may refuse your contract being ended.

that is not true. the supreme court has ruled in G.R. No. 149859

"While probationary employees enjoy security of tenure such that they cannot be removed except for just cause as provided by law, such protection extends only during the period of probation. Once that period expired, the constitutional protection could no longer be invoked.

Legally speaking, petitioner was not illegally dismissed. His contract merely expired. But we have ruled in Manlimos et al VS NLRC that this constitutional protection ends on the expiration of the probationary period. On that date, the parties are free to either renew or terminate their contract of employment. Manlimos concluded that “(t)his development has rendered moot the question of whether there was a just cause for the dismissal of the petitioners"

probationary contracts do have expiration dates if it is explicitly cited in the contract.  Thus the employer has the option of merely letting a contract expire instead of the typical evaluation method.  

However it is important to distinguish evaluation period milestones and the end of the contract

I don't want to become a regular employee here in our company, however they said I cannot refuse to become a regular employee.

They are wrong. The right of employment carries with it the right not to be employed. This right is protected by the Constitution. 'The right against Involuntary Servitude'.

Just iform your Management that you intend to finish the remainder of your Proby term.

Thank you for your responses. If I were to refuse to be regularized I have to pay for damages that's what our HR told me when I asked her about this issue.

They have to prove first what "damages" you have to pay for.

let me just clarify, you want to stop your employment after the probationary date? Or you want to continue working you just dont want to become a regular employee (which doesn't make sense)

They have to prove first what "damages" you have to pay for.

Sir naka-indicate sa contract na If I won't be able to finish my contract I have to pay for damages and the same applies with refusing to become a regular employee, do they still have to prove it? Gusto ko sana Sir maka-alis na sa company pero ang kinakatakot ko yong pwedeng habulin nila sa akin. Any advice na pwedeng idahilan for my immediate resignation?Thanks.

let me just clarify, you want to stop your employment after the probationary date? Or you want to continue working you just dont want to become a regular employee (which doesn't make sense)

I want to stop my employment after the probationary date (before) but right now I dont want to finish my contract. Now I'm seeking for an advice how to leave the company safely and avoid any damages I have to pay. Thank you.

i suggest you just finish your contract.. submit a resignation letter 30 days before your probi ends.