My employer breached the contract that we had both signed

The scenario:

It's my first work after graduation & passing the board, had my first month of being employed last December 21, 2011.

I had signed an employment contract together with the signature of the HR-head being the representative of the the company I'm working with.

After a month of service, the company breached the contract by not following the stipulations & changing some without my consent.

Right now, as I'm writing this inquiry, I listed provisions that my employer violated. Also, I provide explanations for them to know what have they violated.

Provisions from the Civil Code of the Philippines that I'm about to use:

1. Article 1308
The contract must bind both contracting parties; its validity or compliance cannot be left to the will of one of them.

2. Article 1370
If the terms of the contract are clear and leave no doubt upon the intention of the contracting parties, the literal meaning of the stipulations shall control.
If the words appear to be contrary to the evident intention of the parties, the latter shall prevail over the former.

3. Article 1338
There is fraud when, through the insidious words or machinations of one of the contracting parties, the other is induced to enter into a contract which, without them, he would not have agreed to.

4. Article 1339
Failure to disclose facts, when there is a duty to reveal them, as when the parties are bound by confidential relations, constitutes fraud.

5. Article 1170
Those who in the performance of their obligations are guilty of fraud, negligence, or delay, and those who in any manner contravene the tenor thereof, are liable for damages.

6. Article 2201
In contracts and quasi-contracts, the damages for which the obligor who acted in good faith is liable shall be those that are the natural and probable consequences of the breach of the obligation, and which the parties have foreseen or could have reasonably foreseen at the time the obligation was constituted.
In case of fraud, bad faith, malice or wanton attitude, the obligor shall be responsible for all damages which may be reasonably attributed to the non-performance of the obligation.

With regards to the termination of employee that requires one (1) month prior notice as per Philippine Labor Code is concern, I conclude that my employer as the one who breach the contract lose their right to exercise such.

Being the injured party, I have the right to resign without me being bound for damages, am I right sir?

Just in case if it's being corrected, as to legal point of view do I have the right to demand for a retroactive correction? It's because as to my common sense & as to International Accounting Standard(IAS)/Philippine Accounting Standard(PAS) # 8: Accounting Policies, Changes in Accounting Estimates and Errors*
As a general rule, retroactive correction is a must. Criterion for the exemption to the rule are not met. Also, I'm entitled to claim for damages pursuant to the provisions I enumerated..

*Prior period errors are omissions from, and misstatements in, an entity's financial statements for one or more prior periods arising from a failure to use, or misuse of, reliable information that was available and could reasonably be expected to have been obtained and taken into account in preparing those statements. Such errors result from mathematical mistakes, mistakes in applying accounting policies, oversights or misinterpretations of facts, and fraud.