I had to choose my dissertation topic, but due to some technical problems the wrong choice was selected. I wanted to know how much will it affect when I'm looking for a job. My major is accounting and finance and the topic that was chosen is much more theoretical i.e corporate social responsibility. What should be done?
Short answer: no, not really
Although it sometimes happens, it is quite rare for the topic of a dissertation to align with later professional work --- a fortiori when it is only a bachelor dissertation. Most of the time the bachelor degree functions as a means of giving broad tertiary instruction in a field and then signalling baseline competence in that field. Even for people who go on to do PhDs, it is common that their disseration topic will diverge from their later professional work.
There is perhaps a (very) slight advantage if you end up practicing in a field where your bachelor dissertation directly relates to your professional work. It gives you a very minor headstart, but it is only minor, since you will get better and better at your job, and your musings as an undergraduate will later seem like they are not of high quality. For a bachelor dissertation the usual expectation is that you are learning a topic area and able to say something sensible about it, but you are not usually expected to contribute publishable research.
As to what should be done in your particular case, you haven't set out your available options, but in any case, I really don't think it's a big deal that you are doing a topic outside your major. It is an opportunity to learn about a topic that is not the focus of your major, which will give you a more-rounded education in the field. So long as you have no strong aversion to the topic (e.g., extreme boredom of it) then I would suggest you accept this topic and get stuck in.
[This answer is from a North American perspective; it may apply less elsewhere. And it speaks in generalities.]
When industry is hiring at the Bachelor's level, they are generally looking for general academic success, an overall knowledge of a broad area (the "major"), and some evidence of ability for independent work (evidenced, for instance, by a major senior paper, project, or thesis.) They are fairly rarely looking for specialized knowledge in a small area that would have been developed specifically within the context of such a project or thesis. This is unlike at the Masters' and Ph.D. levels, after which specific expertise developed during one's thesis/dissertation work is much more likely to be directly relevant for the job one gets hired into.
With that in mind, if your major is in field A, you should not be penalized for having done a major project in subfield X while seeking a job in subfield Y.
That being said, as a former academic as well as someone who hired undergrads into industry, those hiring often look for consistent good academic performance as well as a sense of purpose, and a narrative to match.
So if I'm hiring you for Y, your thesis/project in X may be a missed opportunity to demonstrate interest and knowledge in Y. If you can demonstrate that elsewhere in your CV/application/interview, and if you have any sort of narrative why a project in X was interesting for you, I'll be unworried. If you fit the pattern of someone flighty who is interested in something different every week, and has no pattern of engagement with Y anywhere, then I will be worried.
In this instance, it seems X=CSR, and I'm not sure what subarea of accounting and finance Y is. I also find the wording "due to technical problems the wrong choice was selected" a bit unusual, so I hope you have a reason coming from your personal interest why you're writing on CSR, not just checking the wrong box somewhere!
There are too many variables to give a definite response. It could matter. It might not matter at all. I think that in most fields, at least, it is still rare for undergraduates to write a thesis. If that is so in your field, then anything you write is probably a plus.
It also depends on the type of job you want, as well as your future aspirations, e.g. graduate study.
But employers can be picky. If you write things that are seen as controversial, it could hurt. But, in general, thinking and writing are valued by many, if not most, employers. I doubt that too many employers will look at more than the title and the grade, though.
And, you also likely have an advisor who can give you advice on this.