I had a nite eye which wouldn't zero. They took it in, told me it was screwed and offered the 50% off a new scope. Bit like angry bear, nothing came close to the range of zoom I had (in specs), unless I paid about £200 odd (or £100 after discount)
I settled for a 4-12x40/42? vantage at half price (think I paid £45) and to be fair it's a much better scope than the nite eye was. So I've been left happy in the end.