Guantamo in Belgium?

Yesterday was a good day. Isa called just when I had left the apartment to go downtown to get a haircut, we agreed that we would meet at hers in the evening. I went to the supermarket and bought asparagus and new potatoes, we both like that.
Having been early for my 15.30h haircut, I decided to go to FNAC and look for some books. I picked up a box from a shelve which I 10 minutes later returned to a different shelve, having been focused on a podcast about food and cooking I was listening to. I remembered that I still needed some wine and a lemon for dinner and decided to leave the store.
I was stopped by a security person and asked to follow to a room behind, where I was asked to hand out what I had stolen. Surprised, I stated that I had not stolen anything.
A second person came in with a box, which packaging had been damaged and offered me to pay for the box or to call the police. Obviously a misunderstanding, I asked to call the police. The police arrived later, took my personal information, interogated me suggesting I tried to steal the box, which I denied. I was taken to the police station in handcuffs and, after being strip-searched, put into a prison cell awaiting a certified English speaking interogator.
I was then lead to a room with 4+ police personel and being cross-examined with leading questions. One of the police personel asked me if I would agree to a house-search in my presence. I then asked what my rights & obligations were and was informed that 'this is not America', but given the interview form, which actually gives some indications of rights. Consequently I asked that all questions put to me are recorded in writing, so are my answers. This is stated as one of the 'rights'.
However, this was denied when a higher-ranking officer came in and suggested I do a statement instead, spend the night in a prison cell and see a judge the following morning.
My request to make a telefon call was denied.
I was put into a prison cell around 16.30-17.00h and left there until about 8.45h the following morning, without water being offered let alone anything to eat. The methods used are similiar to publications about US war prisons, including sleep deprivation through light and noise, yelling at and intimidating of other prisoners; unhygenic conditions such as a broken toilet seat and a toilet which can not be flushed.
In the morning I was taken, handcuffed, to another police station near the Palais de Justice and put into another prison cell.
Around 11.45h I was handcuffed again and led to a different floor in the building to see a judge. In the presence of a translator and a secretary, the judge explained that the state prosecutor demanded that I would be put in prison again for the day. He then asked for my personal information, whether I had been sentenced or in contact with a court before, which I denied. I repeated that I still stand to my statement made the previous day at the police station and that I did not try to steal anything.
I also denied that I objected at any point to a house search, which, I now learned, was stated in the police report. I repeated that, when asked if I agreed to a house search, I asked what my rights & obligations were; that I demanded that the police' questions and my answers would be recorded; that the police had not agreed to that but decided to let me write my own statement. The question of a house search did not come up again.
I told the judge that I have no objection at all that a searching on my address would be carried out.
The interrogation was closed at 12.05h and I was free to leave. The judge informed me that he will issue a search warrant for my apartment and that I should open the door in case the police arrives.
I recovered my belongings, left the police department and half way home realised that I forgot my two shopping bags. I returned to the police station and witnessed that the 4 police persons who entered the building with me were asking for me. I collected my bags and went with them to my apartment, which they searched between 12.30-13.00h, leaving me with a copy of a statement that nothing 'abnormal' was found and nothing been confiscated.

I am stunned and not sure what to do next. Still shocked about the way and out-of-proportioness I was treated the last 24 hours.