as a starting point, you are obliged to participate in offers from the Jobcenter, if you want to keep your dagpenge. This is stated in the law (Bekendtgørelse om rådighed, §12, stk. 3).
However you are only obliged to participate in the activities mentioned in your "Min Plan", which you and the Jobcenter hopefully have agreed about.
Virkomhedspraktik must be mentioned as one of the activities that you have agreed with Jobcenter in your "Min Plan" to participate in.
When the Jobcenter gives you an offer, the Jobcenter must ensure that only offers that you are obliged to participate in is offered to you.
So I would recommend that you ask your Jobcenter where in the law (what specific rules) and your "Min Plan" it says that you are obliged to participate in virksomhedpraktik two times within a short period.
But you must be willing to - and also show to Jobcenter that you are willing to - work...or at least increase your chances to get a job.
If you do not act like a person who are interested in getting a work as soon as possible, then the Jobcenter have some additional steps they can take against you, i.e. they can offer you virksomhedspraktik as a way to determine if you are interested in finding a job (to find out if you meet the requirement of being available for the labour market).
Virksomhedspraktik is one of several ways to try to get better chances to have a real job again.
When you receive dagpenge you are obliged to participate in activities that can make your chances for getting a real job better. This is also called "aktivering". Aktivering can be different kind of things so if you don't like virksomhedspraktik and don't think this is the best way to increase your chances of getting into work you can ask the Jobcenter to be activated in another way, for instance participate in education. This must be agreed in the "Min Plan".
Also when you receive dagpenge you are obliged to be available for the labour market. This is called "rådighedsforpligtelsen" (availability requirement).
You have the option to find a company yourself where you can be in virksomhedspraktik.So you are not obliged to accept the specific virksomhedspraktik that the Jobcenter offers you, if you can find one yourself.
You can only deny to participate in offers from the Jobcenter if you can document that you within the next 6 weeks will start full-time regular employment, flex job, maternity leave, surrender to early retirement, or retirement pension.
Anders Weber, www.a-kasser.dk