removal of benefits

Hi, I'm new here. I'd like to ask, 6 years na ako sa current company, and we were given company service vehicle (since assigned kami to do field work) namin na naiuuwi namin everyday. Ngayon, nagkaroon ng new management and they're deciding na ipaiiwan na lang ang sasakyan sa company premises and hindi na pwede iuwi. Pwede ba sila basta-basta magdecide ng ganun kahit matagal nang benefit ng mga empleyado yun?
Also, another question, since field kami assigned, makatarungan ba na i-require kami pumasok ng 7am everyday and umuwi ng past 7pm from Monday-Saturday? We're talking about a well-known multi-national company na may press release na maka-pamilya sila, pero kabaligtaran iniimplement nila sa mga empleyado nila. You're advise will be greatly appreciated. Thank you

You can file dimunition of benefits

Check first the definition of "benefit" if your situation is covered.

It might not be a benefit if it is not given to everyone.

Employee benefits are compensations given to employees in addition to regular salaries or wages.Some benefits are legally required, e.g., social security benefits, medicare, retirement benefits, maternity benefits, service incentive leave, etc. Other benefits are offered by the employer as an incentive to attract and retain employees as well as increase employee morale and improve job performance.

Supplements include those benefits or privileges granted to an employee for the convenience of the employer, e.g., board and lodging within the company premises.

the benefit was not removed..nandon pa din naman yung sasakyan.. for official use only nga lang.. nothing wrong with that.