Hi, I bought a lens from mpb in ‘like new’ condition and there is a fabric hair within the lens large enough to appear on all photos above f/5.6. I couldn’t open the parcel until now (3 weeks later) as I was away for uni and so just discovered the issue today. Mpb refuse to do anything about it and told me to get it cleaned for ‘cheap’ at a camera repair shop but that it will also void my warranty. Is there anything I can do?