XZ1: Any dust on sensor issues?

After 4 months of use, I just noticed a big piece of dust, almost in the center of the sensor...

Indeed it happens, but I was not expecting it so early. already had the issue with DSLRs, but at least you can clean it yourself... And moreover, here, no Dust cleaning system... a bit disappointing.

I'll try sending it back to Olympus, thanks for all your comments.