You have the absolute right to reject, in the same way as an employer who refuses to applicants. But your relationship to remain civilized, call the above number or email response to an invitation letter, sent in by e-mail. Thank you for the invitation and for the time that the company has spent on you, tell them that you have already accepted the invitation to other organizations that you are satisfied. You can even not explain the cause of failure, and you know and do not ask. Demonstrate just common courtesy, adopted in the environment business.
But in the event that a job offer that you are not satisfied, came at a time when you got registered in the public employment service and start receiving benefits, will be difficult to refuse. The law limits the number of failures that you can afford. After only two such cases, you may lose benefits, and you will be deprived of the status unemployed.
Refers to the fact that the proposed vacancy does not match your experience and qualifications. Valid reason for refusal can be above normal territorial remoteness, which is set for each region, or that the conditions for a new job does not correspond to those which you use at your last job.
If your company to be reorganized, changing working conditions or reduction, then you can also get a proposal to change jobs. In this case, you can safely give it up, if for some reason it does not suit you. The reasons you must specify in the application for dismissal, which may occur no earlier than two months after you give written notice of the new workplace. This time you can safely spend finding a new job.