Does a contract of service employees deserve a fair treatment from the company?

yes ,they deserve fair treatment to be satisfied then satisfaction increases their loyalty and improve their performance

100% yes! if employees aren't getting what they deserve or at least what they are promised, then I don't think the Company will be in the business for a very long time because the service that will be provided won't be 100% satisfactory. 

Thanks

No doubt they deserve fair treatment, at the end, they are employees deliver and offer services to mentioned company and they spend their time inside it , so they should be treated just as others.