IPS glow is a sort of metallic sheen that IPS screens have, and that's normal. I think you are talking about bleed, which is a light leaking through in certain areas, usually the corners. I suspect that all retailers are a bit resistant to accepting monitors back on grounds of bleed, they must be sick of it.
You can return it on grounds of it being faulty, but the poroblem is that bleed is somewhat subjective so they may or may not agree with you. Or if it's within 14 days you can just say you have changed your mind and are returning it under distance selling regs. Either way you should know their terms so you know who is paying for what and so on.