In your case I would complain and have them remake the boards for you.
My story with JLCPCB…
I have previously had all my boards made at SeeedStudio.
This time round I was doing my first ever 4 layer board. Shopping around I found that JLCPCB had the best deal for my requirements.
Searching the EEVBlog forum, there are mixed opinions about JLCPCB, however most are favourable.
I ordered: Panelising service – 6 per panel. 10 panels, ENIG, 1mm thick. Paste stencil. DHL. US$62.
Delivery was very quick and I was quite pleased.
Upon closer inspection, they have changed the solder mask on just one pad.
The strange thing is that it is not filled in, but consists of lines of solder mask.
This error is not in my gerbers, JLCPCB changed it.
The stencil is fine – as per my paste layer gerber.
I have not complained as the mask is easy to remove prior to paste and I am only using them in hobbyist quantity. If I was producing this commercially I would definitely complain.

