Refused Xbox one S repair

My xbox one s wouldn't turn on, it would stay on for one second and turn off again. Reading a few posts on different gaming communities, I've decided to sent mine to the service centre.

I will have to mention that it has barely been used as I use to keep it in the bedroom. Sent it to the service centre in it's originall box, protected by the cellulose protective bits.

Over 2 week later it comes back with a letter sayin that they will not fix it as the seal was tampered with and my warranty was also cancelled. I am in shock as I know that the seal was in perfect condition when I sent it. At a closer look after receiving
it, it was tampered indeed and also I've tried to plug it in and this time there was no power what so ever going into device

Now I do not understand when that happened and why there are now so many customers being refused to fix this so very common problem with this model.

To me that sound sounds very unprofessional and I think I deserve some explanation as this level of customer service is the worst I have ever experienced.

:)