Shall I be listed as technical program committee member if I accepted an invitation and did three reviews?
I am not sure if I understand you correctly. Basically, there are two ways to interpret your question:


Interpretation a) you have been invited as a member of the programme committee, did the duties associated to the role in this conference (for instance, but not necessarily restricted to, reviewing papers). In this case the answer is unsurprisingly that yes, you should be listed as a member of the programme committee. It is completely acceptable to remind the organizers to add you to the website if your name is not listed if other PC members are (it is conceivable although unusual that a conference would just not list the PC on the website).
Interpretation b) you have specifically not been invited as a PC member, but as a reviewer (or in whatever other role), but you feel that you did the same work as a PC member. In this case, I am sorry to say that there is no obligation for the conference to somehow upgrade your status, and mailing them about it is unlikely to lead to anything else than you seeming somewhat needy. It is not uncommon or immoral for conferences to distinguish between different roles (e.g., reviewers without voting powers and PC members with voting rights in the PC meeting), even if most of the "work" (writing reviews to papers) is the same or similar. That reviewers don't get mentioned in your case is certainly unfortunate, and you have every right to just not agree to be a reviewer anymore for this conference, but it's not inherently immoral or oblige the organisers to upgrade your role to a more visible one. The underlying faulty assumption here (which I assume is an easy to make mistake given how many conferences at least in CS nowadays work), is that reviewing and being in the TPC is the same. While is is indeed true for many conferences, there are plenty of exceptions as well. In many, particularly very strong, conferences, there are multiple layers of reviewers, PC members, senior PC members, track chairs, and program chairs, with increasing impact on the actual selection.